This release includes 1 security fix following the security policy:
- crypto/x509: mitigation for security concerns with a specific Certificate Authority
We're blocking trust in a small set of intermediate certificates due to specific security concerns around their operation.
Verify will now filter out chains which contain these intermediates, preventing them from being returned to the caller.
We highly recommend immediately upgrading to this release.
This is CVE-2026-111943 and Go issue https://go.dev/issue/82345.
release notes: https://go.dev/doc/devel/release#go1.27.3
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
Exclude the core/runtime/v2/README.md symlink in the links workflow so
lychee does not fail resolving relative links from the symlink path.
docs/runtime-v2.md is already validated directly.
Update broken, moved, and rate-limited links across markdown documents:
- Replace moved Kubernetes cgroup driver and GCP registry docs.
- Replace retired RHEL 6 devmapper docs with kernel.org reference.
- Point NSSM, CRIU, and Ansible references to GitHub repositories.
- Fix relative paths in remote-snapshotter.md and root-relative paths.
Assisted-by: Antigravity
Signed-off-by: Samuel Karp <samuelkarp@google.com>
These releases include 15 security fixes following the security policy:
- net/http: HTTP/2 server crash due to HPACK encoder race
HTTP/2 servers could end up crashing due to inadvertently
modifying its HPACK encoder concurrently. This happens because the
server modifies the HPACK encoder from two goroutines without
synchronization: one uses the encoder to encode a HEADERS frame as part
of a response sent to a client and the other modifies the encoder's
table size when handling a SETTINGS frame containing
SETTINGS_HEADER_TABLE_SIZE that a client sends. A malicious client can
repeatedly send a request while changing the header table size to crash
the server.
Fix this issue by not applying SETTINGS_HEADER_TABLE_SIZE immediately.
Instead, buffer any SETTINGS_HEADER_TABLE_SIZE received, and only apply
the new value prior to the next time the server writes a frame.
Thanks to RyotaK (https://ryotak.net) of GMO Flatt Security Inc. for reporting this issue.
This is CVE-2026-97032 and Go issue https://go.dev/issue/81867.
- net/http: HTTP/2 server memory exhaustion due to Trailer headers
When "Trailer" headers are sent by a client, the HTTP server internally
uses the header values to populate the Request.Trailer map passed to the
server handler. Because Request.Trailer is a map, each entry incurs
memory overhead. For HTTP/2 servers, a malicious client can exploit this
by sending a "Trailer" header that declares a large number of fields,
causing the server to allocate a disproportionate amount of memory while
bypassing Server.MaxHeaderValueCount and Server.MaxHeaderBytes limits.
This exploit is not applicable for HTTP/1 servers, which do not support
multiplexing a large number of requests over one TCP connection, and
whose Server.MaxHeaderBytes are calculated differently.
Server.MaxHeaderValueCount and Server.MaxHeaderBytes limits are now
applied towards the trailer fields declared in "Trailer" headers.
Thanks to RyotaK (https://ryotak.net) of GMO Flatt Security Inc. for reporting this issue.
This is CVE-2026-78659 and Go issue https://go.dev/issue/81857.
- crypto/tls: reject malformed ECH outer extension references
Multiple ECH outer extension references are not
permitted under RFC 9849; previously, a client
could send a well-crafted packet that could
trigger memory exhaustion in the server process
by specifying multiple references.
We now reject these as malformed and curb the
memory amplification vector as a result.
This is CVE-2026-97031 and Go issue https://go.dev/issue/81855.
- cmd/go: checksum bypass for golang.org/fips140
Previously, a user operating inside of a malicious
Go project that defines a bogus golang.org/fips140
and operates a malicious GOMODPROXY the user chooses
to connect to can serve an arbitrary module in its
place.
We now unpack the trusted ziphash for the bundled
golang.org/fips140 module and construct its entry
in the GOMODCACHE such that it can be verified by
the toolchain.
This is CVE-2026-94444 and Go issue https://go.dev/issue/81833.
- cmd/go: checksum database bypass for golang.org/toolchain
Previously, a user operating inside of a malicious
Go project that defines a bogus golang.org/toolchain
go.sum entry and operates a malicious GOMODPROXY the
user chooses to use can bypass the intended checksum.
We now ensure that golang.org/toolchain always goes
to the network for the canonical checksum.
This is CVE-2026-94447 and Go issue https://go.dev/issue/81834.
- html/template: reset context tracking on consecutive template expressions
When a JavaScript template literal contains
consecutive expressions, the context tracking
state was not properly reset upon entering a
new expression.
We now ensure that template-literal expression
entries correctly reset context variables so all
subsequent regular expression literals are
accurately recognized and escaped.
This is CVE-2026-94448 and Go issue https://go.dev/issue/81821.
- html/template: recognize yield as regexp preceder keyword
A trusted template author may have previously
written a valid template wherein the use of
the yield keyword would not be correctly
escaped.
We now ensure that valid keyword uses are
escaped and non-keyword uses are not escaped.
This is CVE-2026-97030 and Go issue https://go.dev/issue/81823.
- net/textproto, mime/multipart: memory limit bypass when parsing MIME headers
Parsing a multipart form could bypass memory limits and read an
arbitrarily long line into memory when the remaining limit at the
start of a part was less than 400 bytes.
Multipart form memory limits are now properly enforced in this situation.
Thanks to Jakub Ciolek (https://ciolek.dev) for reporting this issue.
This is CVE-2026-94440 and Go issue https://go.dev/issue/81741.
- net/http: HTTP/1 client connection desynchronization after CONNECT rejection
When http.Transport sends an HTTP/1 CONNECT request with a non-empty
Request.Body, it writes the body directly to the connection without
framing after the request headers. If the server rejects the CONNECT
request with a non-2xx keep-alive response, Transport returns the
connection to the idle pool. Because CONNECT requests do not have a
request body, the server may interpret the trailing body bytes as a
subsequent pipelined HTTP/1.1 request on the connection, leaving the
pooled connection desynchronized and causing the next caller that reuses
it to read the response to the injected request. In reverse proxies
(including httputil.ReverseProxy) that forward CONNECT requests through
a shared Transport, this can lead to cross-user response poisoning.
The HTTP/1 transport now closes a connection after sending a CONNECT
request, regardless of the response status.
In addition, ReverseProxy now rejects incoming CONNECT requests
with a 405 Method Not Allowed response. ReverseProxy has never handled
CONNECT requests in a useful fashion (it does not convert the
connection into a bidirectional tunnel), so we do not expect this
change to negatively affect any current users.
Thanks to Xclow3n (Rajat Raghav) for reporting this issue.
This is CVE-2026-56866 and Go issue https://go.dev/issue/81740.
- net/http: HTTP/1 server connection desynchronization after 2xx CONNECT response
When an HTTP server handler sent a 2xx response to an HTTP/1 CONNECT request
and returned without hijacking the connection, the server improperly continued
to read and serve requests from the connection. Since a 2xx response to an
HTTP/1 CONNECT converts the connection into a tunnel, the server should not
treat the connection as continuing to contain HTTP.
The impact of this misbehavior is mostly limited to potential request smuggling,
where an intermediate proxy considers the data on the connection to be tunneled
and the server considers it to be HTTP.
The HTTP/1 server now always closes a connection after responding to a CONNECT
request, regardless of the response status.
Thanks to Jakub Ciolek (https://ciolek.dev) for reporting this issue.
This is CVE-2026-94439 and Go issue https://go.dev/issue/81744.
- net/http: excessive CPU consumption from repeated initial window changes
A malicious HTTP/2 peer could cause excessive CPU consumption in the
client or server by opening a large number of streams and then sending
many small SETTINGS frames containing SETTINGS_INITIAL_WINDOW_SIZE values.
The HTTP/2 client and server now efficiently handle changes to the
initial window size (O(1) rather than O(number of streams)).
Thanks to Jakub Ciolek (https://ciolek.dev) for reporting this issue.
This is CVE-2026-78669 and Go issue https://go.dev/issue/81742.
- net/http: HTTP/2 transport accepts malformed framing-related headers
Historically, we have been rather lax about malformed framing-related
headers in our HTTP/2 implementation, as they cannot interfere with
HTTP/2 framing. However, this makes it possible for our HTTP/2
implementation to forward responses containing such headers to an HTTP/1
client when acting as a reverse proxy. If the HTTP/1 client also does
not behave strictly enough, this can result in response smuggling.
We now delete malformed framing-related headers when received by our
HTTP/2 transport, so they will not be forwarded to a potentially
vulnerable HTTP/1 client.
Thanks to TJ Barton for reporting this issue.
This is CVE-2026-78660 and Go issue https://go.dev/issue/81115.
- os: Root.Mkdir(All) can follow junctions out of the root on Windows
On Windows, when the target of Root.Mkdir or Root.MkdirAll was a junction
pointing to an empty location, the operation would create a directory at
the junction target even when that target was located outside the root.
This only applies to operations where the last path component is a
junction (path/to/junction, but not path/junction/target).
Root.Mkdir and Root.MkdirAll now correctly avoid resolving junctions.
Thanks to Daniele Ballarini for reporting this issue.
This is CVE-2026-56857 and Go issue https://go.dev/issue/81739.
- net/http: lack of limit on size of parsed Range headers
When parsing a Range header containing a large number of small ranges,
FileServer(FS), ServeContent, and ServeFile(FS) could consume an excessive
amount of CPU.
These functions now ignore Range headers containing more than 200 ranges.
The limit is controlled by the new httpservecontentmaxranges=
GODEBUG setting. Setting GODEBUG=httpservecontentmaxranges=0
disables the limit.
Thanks to Jakub Ciolek (https://ciolek.dev) for reporting this issue.
This is CVE-2026-78667 and Go issue https://go.dev/issue/81858.
- net/http: double flow control refund on HTTP/2 server streams
The HTTP/2 server could refund connection-level flow control twice for the same data:
Once when a client resets a stream (refunding data for any sent-but-unread portion
of the stream), and again when a request handler reads the buffered data.
A malicious client could exploit this to bypass the configured connection-level
flow control limit (MaxReceiveBufferPerConnection). Total buffered data is still
limited by the concurrent stream limit and stream-level flow control.
The HTTP/2 server now waits to refund connection-level flow control for reset
streams until after the request handler is complete.
Thanks to Ali Sherif (https://www.linkedin.com/in/ali-sherif-13812b276/) for reporting this issue.
This is CVE-2026-78663 and Go issue https://go.dev/issue/81743.
release notes: https://go.dev/doc/devel/release#go1.27.2
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
The default seccomp profile excludes AF_VSOCK for direct socket calls,
but 32-bit x86 binaries can reach it through socketcall because
seccomp cannot inspect the pointer argument.
Deny the family in AppArmor so the socket_create LSM hook closes that
path and prevents default-profile containers from reaching host or
guest VSOCK services.
This mirrors moby/profiles commit b7711bef4ad769a13fd40fe1ba710ad0f796fcfd
("apparmor: Deny AF_VSOCK sockets in default container profile").
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
The AF_ALG address family exposes the Linux kernel crypto API to
userspace via sockets. This has been a source of container escape
vulnerabilities (see https://copy.fail/).
Unlike seccomp, which can only filter arguments of the direct
socket(2) syscall, AppArmor hooks into the kernel's
security_socket_create() LSM callback, which fires regardless of the
syscall entry point. This means AppArmor also blocks AF_ALG sockets
created via the legacy socketcall(2) multiplexer (used by 32-bit
binaries), which seccomp cannot inspect because the address family is
behind a userspace pointer that BPF cannot dereference.
The "deny network alg," rule is placed right after the blanket
"network," allow rule so the deny takes precedence for this specific
address family.
This mirrors moby/profiles commit 946fe8e08d9debcafe76ee60d69261a0c0990368
("apparmor: Deny AF_ALG sockets in default container profile").
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
The default profile allowed socket(2) through open-ended range checks
around AF_ALG and AF_VSOCK. Any address family added to Linux later was
allowed automatically.
List the Linux address families the default profile supports and build
the socket rules from that list.
AF_ALG and AF_VSOCK stay blocked, and unknown or future domains now get
the default EPERM response.
A single rule cannot bound both ends of a range, because runc treats
repeated comparisons on one argument as OR.
The consecutive run starting at AF_UNIX therefore becomes one less-than
rule, which is safe because AF_UNSPEC cannot be created. Every other
domain gets its own equality rule.
This matches the same change in Moby's default seccomp profile.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
Go 1.27 has been released and we can re-enable matrix
building with min and max Go versions as well as move
most of CI jobs to use the latest Go 1.27. Leave install-go
action at 1.26.6.
Signed-off-by: Phil Estes <estesp@amazon.com>
Remove support for restoring checkpoint data during CreateContainer,
which was previously deprecated in v2.3.
Assisted-by: Antigravity
Signed-off-by: Samuel Karp <samuelkarp@google.com>
Add a new `enable_criu` configuration option under CRI plugin runtime
settings. When set to false, any checkpoint or restore request will fail
fast with an error indicating that CRIU support is disabled by
configuration. `enable_criu` currently defaults to true.
Add an integration test script to verify that setting `enable_criu` to
false in containerd configuration successfully disables checkpoint and
restore operations and fails fast.
Assisted-by: Antigravity
Signed-off-by: Samuel Karp <samuelkarp@google.com>
go1.26.4 includes security fixes to the crypto/x509, mime, and
net/textproto packages, as well as bug fixes to the compiler, the
runtime, the go fix command, and the crypto/fips140 package
Signed-off-by: Akhil Mohan <akhilerm@gmail.com>
Filter out any annotations on the checkpointed container matching
`cdi.k8s.io/` or exactly `cdi.k8s.io` during restore to prevent
unauthorized device restoration. When an annotation is denied, a warning
log is generated.
Tested by:
* Unit tests for exact matching, prefix boundaries, and metadata merging
* Complete CRI integration and checkpoint restore suite
Assisted-by: Antigravity
Signed-off-by: Samuel Karp <samuelkarp@google.com>
Under slow network conditions (e.g., simulated 2 Mbps ingress bandwidth
limits in CI), restoring a container from a checkpoint can fail if it
requires pulling the base image again.
During restore, crictl create is called. In test_from_oci, it used a
10-second timeout (crictl -t 10s create). Over a 2 Mbps connection,
pulling the 2.8MB Alpine layer takes ~12-13 seconds, causing the
operation to exceed the timeout and fail with context canceled.
Increase the timeouts in both test_from_archive and test_from_oci to
30 seconds. This ensures the base image pull can complete successfully
even in constrained CI environments.
Tested:
Ran the CRI integration tests on a GCE VM under a simulated 2 Mbps
ingress bandwidth limit using traffic control (tc). Verified that
both test_from_archive and test_from_oci passed successfully and
container restore completed without timeout.
Assisted-by: Antigravity
Signed-off-by: Samuel Karp <samuelkarp@google.com>
AF_ALG (address family 38) exposes the Linux kernel crypto API to
userspace via socket(2). Containers have no legitimate need for this
interface under the default profile, and leaving it accessible widens
the kernel attack surface unnecessarily (see https://copy.fail/).
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
This release include 11 security fixes:
- cmd/go: malicious module proxy can bypass checksum database
A malicious module proxy could exploit a flaw in the go command's
validation of module checksums to bypass checksum database validation.
This vulnerability affects any user using an untrusted module proxy
(GOMODPROXY) or checksum database (GOSUMDB).
A malicious module proxy can serve altered versions of the Go toolchain.
When selecting a different version of the Go toolchain than the
currently installed toolchain (due to the GOTOOLCHAIN environment variable,
or a go.work or go.mod with a toolchain line), the go command will download
and execute a toolchain provided by the module proxy. A malicious module
proxy can bypass checksum database validation for this downloaded
toolchain.
Since this vulnerability affects the security of toolchain downloads,
setting GOTOOLCHAIN to a fixed version is not sufficient. You must upgrade
your base Go toolchain.
The go tool always validates the hash of a toolchain before executing it,
so fixed versions will refuse to execute any cached, altered versions of the
toolchain.
The go tool trusts go.sum files to contain accurate hashes of the current
module's dependencies. A malicious proxy exploiting this vulnerability to
serve an altered module will have caused an incorrect hash to be recorded
in the go.sum. Users who have configured a non-trusted GOPROXY can determine
if they have been affected by running "rm go.sum ; go mod tidy ; go mod verify",
which will revalidate all dependencies of the current module.
The specific flaw in more detail:
The go command consults the checksum database to validate downloaded modules,
when a module is not listed in the go.sum file. It verifies that the module hash
reported by the checksum database matches the hash of the downloaded module.
If, however, the checksum database returns a successful response that contains
no entry for the module, the go command incorrectly permitted validation to succeed.
A module proxy may mirror or proxy the checksum database, in which case the go
command will not connect to the checksum database directly. Checksums reported
by the checksum database are cryptographically signed, so a malicious proxy
cannot alter the reported checksum for a module. However, a proxy which returns
an empty checksum response, or a checksum response for an unrelated module,
could cause the go command to proceed as if a downloaded module has been validated.
The go command now properly checks checksum database responses to ensure
that the expected module signature is present, not just that if a signature is
present it matches the expectation.
Thanks to Mundur (https://github.com/M0nd0R) for reporting this issue.
This is CVE-2026-42501 and Go issue https://go.dev/issue/79070.
- net/http/httputil: ReverseProxy forwards queries with more than urlmaxqueryparams parameters
When used with a Rewrite function, or a Director function which parses query parameters,
ReverseProxy sanitizes the forwarded request to remove query parameters which are not
parsed by url.ParseQuery. ReverseProxy did not take ParseQuery's limit on the total number
of query parameters (controlled by GODEBUG=urlmaxqueryparams=N) into account.
This could permit ReverseProxy to forward a request containing a query parameter
that was not visible to the Rewrite function.
For example, the query "a1=x&a2=x&...&a10000=x&hidden=y" could forward the parameter
"hidden=y" while hiding it from the proxy's Rewrite function.
ReverseProxy now avoids forwarding parameters that exceed the ParseQuery limit.
This is CVE-2026-39825 and Go issue https://go.dev/issue/78948.
- net: panic in Dial and LookupPort when handling NUL byte on Windows
The Dial and LookupPort functions would panic on Windows when provided
with an input containing a NUL (0). These functions now return an error
rather than panicking.
This is CVE-2026-39836 and Go issue https://go.dev/issue/79006.
- net/mail: quadratic string concatenation in consumePhrase
Pathological inputs could cause DoS through consumePhrase
when parsing an email address according to RFC 5322.
This is CVE-2026-42499 and Go issue https://go.dev/issue/78987.
- net/mail: quadratic string concatentation in consumeComment
Well-crafted inputs reaching ParseAddress, ParseAddressList,
and ParseDate were able to trigger excessive CPU exhaustion
and memory allocations.
This is CVE-2026-39820 and Go issue https://go.dev/issue/78566.
- cmd/go: "go bug" follows symlinks in predictable temporary filenames
The "go bug" command wrote to two files with predictable names in
the system temporary directory (for example, "/tmp").
An attacker with access to the temporary directory could create a
symlink in one of these names, causing "go bug" to overwrite the
target of the symlink.
The "go bug" command now uses os.MkdirTemp to create a safe
working directory.
Thanks to Harshit Gupta (Mr HAX) for reporting this issue.
This is CVE-2026-39819 and Go issue https://go.dev/issue/78584.
- cmd/go: "go tool pack" does not sanitize output paths
The "go tool pack" subcommand is a minimal version of the Unix ar utility.
It is used by the compiler as an internal tool with known-good inputs.
The "pack" subcommand did not sanitize output filenames.
When invoked to extract a malicious archive file, it could write
files to arbitrary locations on the filesystem.
The "pack" subcommand now refuses to extract files with names
containing any directory components.
Thanks to Harshit Gupta (Mr HAX) for reporting this issue.
This is CVE-2026-39817 and Go issue https://go.dev/issue/78778.
- net/http: infinite loop in HTTP/2 transport when given bad SETTINGS_MAX_FRAME_SIZE
When processing HTTP/2 SETTINGS frames, transport will enter an infinite loop of
writing CONTINUATION frames if it receives a SETTINGS_MAX_FRAME_SIZE with a
value of 0.
This allows potential DoS against a client by a malicious server. HTTP/2
transport now properly checks that the received SETTINGS_MAX_FRAME_SIZE is
valid.
Thanks to Marwan Atia (marwansamir688@gmail.com) for reporting this issue.
This is CVE-2026-33814 and Go issue https://go.dev/issue/78476.
- html/template: escaper bypass leads to XSS
If a trusted template author were to write a
tag containing an empty type attribute or a type
attribute with an ASCII whitespace, the execution of
the template would incorrectly escape any data passed
into the block.
Thanks to Mundur (https://github.com/M0nd0R) for reporting this issue.
This is CVE-2026-39826 and Go issue https://go.dev/issue/78981.
- net: crash when handling long CNAME response
When using LookupCNAME with the cgo DNS resolver,
a very long CNAME response could trigger a double-free of C memory
and a crash. The double-free has been fixed.
Thanks to hamayanhamayan for reporting this issue.
This is CVE-2026-33811 and Go issue https://go.dev/issue/78803.
- html/template: bypass of meta content URL escaping causes XSS
CVE-2026-27142 fixed a vulnerability in which URLs were not
correctly escaped inside of a tag's attribute.
If the URL content were to insert ASCII whitespaces around the
= rune inside of the attribute, the escaper would
fail to similarly escape it, leading to XSS.
Dynamic inputs to a tag's attribute are now
whitespace sanitized prior to escaping.
Thanks to Samy Ghannad for reporting this issue.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
Add a comment explaining the purpose of the socket rules and noting that
on 32-bit x86, socket() goes through socketcall(2) which is allowed
unconditionally, so these arg filters only apply to the direct socket
syscall.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
The "abi" keyword was added for apparmor 3.0
The original change to add this ended up breaking versions < 3.0.
The abi itself is a macro in /etc/apparmor.d so we can check if the
macro exists to determine if we *can* set an abi in the template.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
This change updates the Go version from 1.26.0 to 1.26.2 across the
repository, including CI configurations, build scripts, and development
environments.
Signed-off-by: Sergey Kanzhelev <S.Kanzhelev@live.com>
This change updates the Go version from 1.25.8 to 1.26.0 across the
repository, including CI configurations, build scripts, and development
environments.
It also fixes two linter issues discovered after upgrading the Go version:
- core/snapshots/storage/bolt.go: incorrect printf format for uint64
- plugins/transfer/plugin.go: incorrect printf format for int and unused variable
The golangci-lint version in script/setup/install-dev-tools is also updated to v2.9.0
to match CI.
Signed-off-by: Sergey Kanzhelev <S.Kanzhelev@live.com>
FuzzArchiveExport and FuzzCSWalk were using context.Background()
without timeout, causing occasional test failures when certain fuzz
inputs triggered slow operations that exceeded the 30s fuzztime limit.
Add 25s timeout to both tests, leaving 5s buffer for cleanup.
Fixes intermittent 'context deadline exceeded' failures in CI.
Signed-off-by: qiuxue <liuyutao36@gmail.com>
go1.25.8 (released 2026-03-05) includes security fixes to the html/template,
net/url, and os packages, as well as bug fixes to the go command, the compiler,
and the os package. See the Go 1.25.8 milestone on our issue tracker for details.
- 1.25.8 https://github.com/golang/go/issues?q=milestone%3AGo1.25.8+label%3ACherryPickApproved
- diff: https://github.com/golang/go/compare/go1.25.7...go1.25.8
- 1.26.1 https://github.com/golang/go/issues?q=milestone%3AGo1.26.1+label%3ACherryPickApproved
- diff: https://github.com/golang/go/compare/go1.26.0...go1.26.1
---
We have just released Go versions 1.26.1 and 1.25.8, minor point releases.
These releases include 5 security fixes following the security policy:
crypto/x509: incorrect enforcement of email constraints
- When verifying a certificate chain which contains a certificate containing
multiple email address constraints (composed of the full email address) which
share common local portions (the portion of the address before the '@'
character) but different domain portions (the portion of the address after the
'@' character), these constraints will not be properly applied, and only the
last constraint will be considered.
This can allow certificates in the chain containing email addresses which are
either not permitted or excluded by the relevant constraints to be returned by
calls to Certificate.Verify. Since the name constraint checks happen after chain
building is complete, this only applies to certificate chains which chain to
trusted roots (root certificates either in VerifyOptions.Roots or in the system
root certificate pool), requiring a trusted CA to issue certificates containing
either not permitted or excluded email addresses.
This issue only affects Go 1.26.
Thanks to Jakub Ciolek for reporting this issue.
This is CVE-2026-27137 and Go issue https://go.dev/issue/77952.
- crypto/x509: panic in name constraint checking for malformed certificates
Certificate verification can panic when a certificate in the chain has an empty
DNS name and another certificate in the chain has excluded name constraints.
This can crash programs that are either directly verifying X.509 certificate
chains, or those that use TLS.
Since the name constraint checks happen after chain building is complete, this
only applies to certificate chains which chain to trusted roots (root
certificates either in VerifyOptions.Roots or in the system root certificate
pool), requiring a trusted CA to issue certificates containing malformed DNS
names.
This issue only affects Go 1.26.
Thanks to Jakub Ciolek for reporting this issue.
This is CVE-2026-27138 and Go issue https://go.dev/issue/77953.
- html/template: URLs in meta content attribute actions are not escaped
Actions which insert URLs into the content attribute of HTML meta tags are not
escaped. This can allow XSS if the meta tag also has an http-equiv attribute
with the value "refresh".
A new GODEBUG setting has been added, htmlmetacontenturlescape, which can be
used to disable escaping URLs in actions in the meta content attribute which
follow "url=" by setting htmlmetacontenturlescape=0.
This is CVE-2026-27142 and Go issue https://go.dev/issue/77954.
- net/url: reject IPv6 literal not at start of host
The Go standard library function net/url.Parse insufficiently
validated the host/authority component and accepted some invalid URLs
by effectively treating garbage before an IP-literal as ignorable.
The function should have rejected this as invalid.
To prevent this behavior, net/url.Parse now rejects IPv6 literals
that do not appear at the start of the host subcomponent of a URL.
Thanks to Masaki Hara (https://github.com/qnighy) of Wantedly.
This is CVE-2026-25679 and Go issue https://go.dev/issue/77578.
- os: FileInfo can escape from a Root
On Unix platforms, when listing the contents of a directory using
File.ReadDir or File.Readdir the returned FileInfo could reference
a file outside of the Root in which the File was opened.
The contents of the FileInfo were populated using the lstat system
call, which takes the path to the file as a parameter. If a component
of the full path of the file described by the FileInfo is replaced with
a symbolic link, the target of the lstat can be directed to another
location on the filesystem.
The impact of this escape is limited to reading metadata provided by
lstat from arbitrary locations on the filesystem. This could be used
to probe for the presence or absence of files as well as gleaning
metadata like file sizes, but does not permit reading or writing files
outside the root.
The FileInfo is now populated using fstatat.
Thank you to Miloslav Trmač of Red Hat for reporting this issue.
This is CVE-2026-27139 and Go issue https://go.dev/issue/77827.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
The current AppArmor profile intends to block write access to everything
in `/proc`, except for `/proc/<pid>` and `/proc/sys/kernel/shm*`.
Currently the rules block access to everything in `/proc/sys`, and do
not successfully allow access to `/proc/sys/kernel/shm*`. Specifically,
a path like /proc/sys/kernel/shmmax matches this part of the pattern:
deny @{PROC}/{[^1-9][^0-9][^0-9][^0-9]* }/** w,
/proc / s y s / kernel /shmmax
This downstreams the patch from [moby@66f14e4] to the containerd profile,
and updates the rule so that it works as intended.
[moby@66f14e4]: https://github.com/moby/moby/commit/66f14e4ae9173f6fb7d1e4a7e13632297bdb8d29
Co-authored-by: Phil Sphicas <phil.sphicas@att.com>
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
This downstreams the patch from [moby@b4a6ccb]:
> drop useless apparmor denies
> These files don't exist under proc so this rule does nothing.
>
> They are protected against by docker's default cgroup devices since they're
> both character devices and not explicitly allowed.
[moby@b4a6ccb]: https://github.com/moby/moby/commit/b4a6ccbc5fe695062111cad5a20bb3d0ac5a94db
Co-authored-by: Tycho Andersen <tycho@tycho.pizza>
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
go1.25.7 (released 2026-02-04) includes security fixes to the go command
and the crypto/tls package, as well as bug fixes to the compiler and the
crypto/x509 package. See the Go 1.25.7 milestone on our issue tracker for
details:
https://github.com/golang/go/issues?q=milestone%3AGo1.25.7+label%3ACherryPickApproved
full diff: https://github.com/golang/go/compare/go1.25.6...go1.25.7
From the security mailing list:
> Hello gophers,
>
> We have just released Go versions 1.25.7 and 1.24.13, minor point releases.
>
> These releases include 2 security fixes following the security policy:
>
> - cmd/cgo: remove user-content from doc strings in cgo ASTs
>
> A discrepancy between how Go and C/C++ comments
> were parsed allowed for code smuggling into the
> resulting cgo binary.
>
> To prevent this behavior, the cgo compiler
> will no longer parse user-provided doc
> comments.
>
> Thank you to RyotaK (https://ryotak.net) of
> GMO Flatt Security Inc. for reporting this issue.
>
> This is CVE-2025-61732 and https://go.dev/issue/76697.
>
> - crypto/tls: unexpected session resumption when using Config.GetConfigForClient
>
> Config.GetConfigForClient is documented to use the original Config's session
> ticket keys unless explicitly overridden. This can cause unexpected behavior if
> the returned Config modifies authentication parameters, like ClientCAs: a
> connection initially established with the parent (or a sibling) Config can be
> resumed, bypassing the modified authentication requirements.
>
> If ClientAuth is VerifyClientCertIfGiven or RequireAndVerifyClientCert (on the
> server) or InsecureSkipVerify is false (on the client), crypto/tls now checks
> that the root of the previously-verified chain is still in ClientCAs/RootCAs
> when resuming a connection.
>
> Go 1.26 Release Candidate 2, Go 1.25.6, and Go 1.24.12 had fixed a similar issue
> related to session ticket keys being implicitly shared by Config.Clone. Since
> this fix is broader, the Config.Clone behavior change has been reverted.
>
> Note that VerifyPeerCertificate still behaves as documented: it does not apply
> to resumed connections. Applications that use Config.GetConfigForClient or
> Config.Clone and do not wish to blindly resume connections established with the
> original Config must use VerifyConnection instead (or SetSessionTicketKeys or
> SessionTicketsDisabled).
>
> Thanks to Coia Prant (github.com/rbqvq) for reporting this issue.
>
> This updates CVE-2025-68121 and Go issue https://go.dev/issue/77217.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
This change sets the AppArmor policy used by containerd to indicate it
is `abi/3.0`. This was chosen based on some code archeology which
indicated that containerd 1.7 came out in March 2023, before the
AppArmor 4.0 ABI. The AppArmor policies themselves date to much older;
the last apparmor version-checks were removed in
4baa1876ba and
c990e3f2ed, and both were looking for
AppArmor 2.8.96 or older, pointing to abi/3.0 being the "correct" one
to pick.
Nothing is preventing containerd from migrating to a newer AppArmor
ABI; note, however, that anything newer than `abi/4.0` will need
modifications to preserve UNIX domain sockets.
This was tested by building a custom k3s v1.35.0+k3s3, with the
following modification:
```
diff --git a/go.mod b/go.mod
index 4e7bacd204..0fcaf76b8f 100644
--- a/go.mod
+++ b/go.mod
@@ -8,7 +8,7 @@ replace (
github.com/cilium/ebpf => github.com/cilium/ebpf v0.12.3
github.com/cloudnativelabs/kube-router/v2 => github.com/k3s-io/kube-router/v2 v2.6.3-k3s1
github.com/containerd/containerd/api => github.com/containerd/containerd/api v1.9.0
- github.com/containerd/containerd/v2 => github.com/k3s-io/containerd/v2 v2.1.5-k3s1
+ github.com/containerd/containerd/v2 => github.com/achernya/containerd/v2 v2.0.0-20260206214308-5e0dce89c422
github.com/containerd/imgcrypt => github.com/containerd/imgcrypt v1.1.11
github.com/containerd/stargz-snapshotter => github.com/k3s-io/stargz-snapshotter v0.17.0-k3s1
github.com/docker/distribution => github.com/docker/distribution v2.8.3+incompatible
```
to use a precursor to this commit.
Once built, the resulting k3s was tested on a brand-new Proxmox installation:
```
root@containerd-test:~# uname -a
Linux containerd-test 6.17.2-1-pve #1 SMP PREEMPT_DYNAMIC PMX 6.17.2-1 (2025-10-21T11:55Z) x86_64 GNU/Linux
root@containerd-test:~# pveversion
pve-manager/9.1.1/42db4a6cf33dac83 (running kernel: 6.17.2-1-pve)
```
Files were copied over:
```
achernya@achernya-dev:~/src/k3s$ scp -r dist/artifacts/ root@containerd-test:
```
and installed
```
root@containerd-test:~# mkdir -p /var/lib/rancher/k3s/agent/images/ /usr/local/bin
root@containerd-test:~# cp artifacts/k3s /usr/local/bin/
root@containerd-test:~# cp artifacts/k3s-airgap-images-amd64.tar.zst /var/lib/rancher/k3s/agent/images/
```
then finally started with `k3s server`. Argo CD was then installed:
```
root@containerd-test:~# k3s kubectl create namespace argocd
namespace/argocd created
root@containerd-test:~# k3s kubectl apply -n argocd --server-side --force-conflicts -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml
[elided]
root@containerd-test:~# k3s kubectl get pods -A
NAMESPACE NAME READY STATUS RESTARTS AGE
argocd argocd-application-controller-0 1/1 Running 0 31s
argocd argocd-applicationset-controller-77475dfcf-6b4cb 1/1 Running 0 32s
argocd argocd-dex-server-6485c5ddf5-ckp5s 1/1 Running 0 32s
argocd argocd-notifications-controller-758f795776-djx69 1/1 Running 0 32s
argocd argocd-redis-6cc4bb5db5-lt9fh 1/1 Running 0 32s
argocd argocd-repo-server-c76cf57cd-mr4mc 1/1 Running 0 32s
argocd argocd-server-6f85b59c87-w6cns 0/1 Running 0 32s
kube-system coredns-6b4688786f-pnds2 1/1 Running 0 4m1s
kube-system helm-install-traefik-crd-cn28g 0/1 Completed 0 4m1s
kube-system helm-install-traefik-hc9gp 0/1 Completed 2 4m1s
kube-system local-path-provisioner-6bc6568469-7wglx 1/1 Running 0 4m1s
kube-system metrics-server-77dbbf84b-nqzsc 1/1 Running 0 4m1s
kube-system svclb-traefik-fe6d3a0b-z7jsp 2/2 Running 0 3m14s
kube-system traefik-5fdc878c8d-cjhx5 1/1 Running 0 3m15s
```
Fixes: #12726
Signed-off-by: Alex Chernyakhovsky <alex@achernya.com>
edb3e08697 removed `script/setup/install-protobuf`
and the tools are now installed through `script/setup/install-dev-tools`
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Paweł Gronowski