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>
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>
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>
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>
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>
- go1.23.7 (released 2025-03-04) includes security fixes to the net/http
package, as well as bug fixes to cgo, the compiler, and the reflect,
runtime, and syscall packages. See the Go 1.23.7 milestone on our issue
tracker for details
- go1.24.1 (released 2025-03-04) includes security fixes to the net/http
package, as well as bug fixes to cgo, the compiler, the go command, and
the reflect, runtime, and syscall packages. See the Go 1.24.1 milestone
on our issue tracker for details.
Signed-off-by: Akhil Mohan <akhilerm@gmail.com>
- go1.23.5 (released 2025-01-16) includes security fixes to the
crypto/x509 and net/http packages, as well as bug fixes to the compiler,
the runtime, and the net package. See the Go 1.23.5 milestone on our
issue tracker for details.
- go1.22.11 (released 2025-01-16) includes security fixes to the
crypto/x509 and net/http packages, as well as bug fixes to the runtime.
See the Go 1.22.11 milestone on our issue tracker for details.
Signed-off-by: Akhil Mohan <akhilerm@gmail.com>
- go1.23.3 (released 2024-11-06) includes fixes to the linker, the
runtime, and the net/http, os, and syscall packages. See the
Go 1.23.3 milestone on our issue tracker for details.
- go1.22.9 (released 2024-11-06) includes fixes to the linker. See
the Go 1.22.9 milestone on our issue tracker for details
Signed-off-by: Akhil Mohan <akhilerm@gmail.com>
- https://github.com/golang/go/issues?q=milestone%3AGo1.23.1+label%3ACherryPickApproved
- full diff: https://github.com/golang/go/compare/go1.23.0...go1.23.1
These minor releases include 3 security fixes following the security policy:
- go/parser: stack exhaustion in all Parse* functions
Calling any of the Parse functions on Go source code which contains
deeply nested literals can cause a panic due to stack exhaustion.
This is CVE-2024-34155 and Go issue https://go.dev/issue/69138.
- encoding/gob: stack exhaustion in Decoder.Decode
Calling Decoder.Decode on a message which contains deeply nested
structures can cause a panic due to stack exhaustion.
This is a follow-up to CVE-2022-30635.
Thanks to Md Sakib Anwar of The Ohio State University for reporting
this issue.
This is CVE-2024-34156 and Go issue https://go.dev/issue/69139.
- go/build/constraint: stack exhaustion in Parse
Calling Parse on a "// +build" build tag line with deeply nested
expressions can cause a panic due to stack exhaustion.
This is CVE-2024-34158 and Go issue https://go.dev/issue/69141.
View the release notes for more information:
https://go.dev/doc/devel/release#go1.23.1
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
