Add a manually dispatched workflow for maintainers to sync a Docker
release branch to a selected release tag.
The sync-release-branch job checks out the release branch, computes
the list of unmerged tags up to the requested tag via
scripts/unmerged-tags, merges them in order via scripts/sync-branch
using git merge --no-ff (resolving conflicts by taking the tag's
content), then pushes the result to a temporary branch.
The push-release-branch job runs after manual approval via the
docker-releases environment. It verifies that neither the release
branch nor the temporary branch moved since the sync job ran before
force-advancing the release branch and deleting the temporary branch.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
go1.26.5 (released 2026-07-07) includes security fixes to the crypto/tls
and os packages, as well as bug fixes to the compiler, the runtime, the
go command, and the net, os, and syscall packages. See the Go 1.26.5
milestone on our issue tracker for details;
- https://github.com/golang/go/issues?q=milestone%3AGo1.26.5+label%3ACherryPickApproved
- full diff: https://github.com/golang/go/compare/go1.26.4...go1.26.5
From the security announcement:
We have just released Go versions 1.26.5 and 1.25.12, minor point releases.
These releases include 2 security fixes following the security policy:
- os: Root escape via symlink plus trailing slash
On Unix systems, opening a file in an os.Root improperly
followed symlinks to locations outside of the Root when
the final path component of the a path is a symbolic link
and the path ends in /.
For example, root.Open("symlink/") would open "symlink"
even when "symlink" is a symbolic link pointing outside of the root.
On Unix, openat(fd, path, O_NOFOLLOW) will follow symlinks
in path when path ends in a /. Root failed to account for
this behavior, permitting paths with a trailing / to escape.
It now properly sanitizes the path parameter provided to openat.
hanks to Mundur for reporting this issue.
This is CVE-2026-39822 and Go issue https://go.dev/issue/79005.
- crypto/tls: Encrypted Client Hello privacy leak
he Encrypted Client Hello implementation would leak the pre-shared key
dentities during the handshake, allowing a passive network observer who can
ollect handshakes to de-anonymize the hostname of the server, even when ECH was
eing used.
Thanks to Coia Prant (github.com/rbqvq) for reporting this issue.
This is CVE-2026-42505 and Go issue https://go.dev/issue/79282.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Add a concurrency group keyed on PR number to prevent duplicate reviews
from simultaneous review_requested events.
Remove the sender.type != 'Bot' guard so Dependabot PRs remain
reviewable — per maintainer feedback, those reviews are useful for
catching behavior changes in dependency updates.
Signed-off-by: Derek Misler <derek.misler@docker.com>
This release include 3 security fixes following the security policy:
- mime: quadratic complexity in WordDecoder.DecodeHeader
Decoding a maliciously-crafted MIME header containing many invalid
encoded-words could consume excessive CPU.
The MIME decoder now better handles this case.
Thanks to p4p3r (https://hackerone.com/p4p3r_hak) for reporting this issue.
This is CVE-2026-42504 and Go issue https://go.dev/issue/79217.
- net/textproto: arbitrary input are included in errors without any escaping
When returning errors, functions in the net/textproto package would
include its input as part of the error, without any escaping. Note that
said input is often controlled by external parties when using this
package naturally. For example, a net/http client uses ReadMIMEHeader
when parsing the headers it receive from a server.
As a result, an attacker could inject arbitrary content into the error.
Practically, this can result in an attacker injecting misleading
content, terminal control bytes, etc. into a victim's output or logs.
This is CVE-2026-42507 and Go issue https://go.dev/issue/79346
- crypto/x509: split candidate hostname only once
(*x509.Certificate).VerifyHostname previously called matchHostnames in a loop
over all DNS Subject Alternative Name (SAN) entries. This caused
strings.Split(host, ".") to execute repeatedly on the same input hostname.
With a large DNS SAN list, verification costs scaled quadratically based on the
number of SAN entries multiplied by the hostname's label count. Because
x509.Verify validates hostnames before building the certificate chain, this
overhead occurred even for untrusted certificates.
Thanks to Jakub Ciolek (https://ciolek.dev) for reporting this issue.
This is CVE-2026-27145 and https://go.dev/issue/79694.
View the release notes for more information:
https://go.dev/doc/devel/release#go1.26.4
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
This makes it easier to verify the sha matches the tag, and may help
with dependabot not updating the version-comment correctly.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
update contributing guide link and improve PR template formatting in `.github/PULL_REQUEST_TEMPLATE.md`
Signed-off-by: Paulchen <lukas.23022005@gmail.com>
Signed-off-by: Lukas Michael <lukas.23022005@gmail.com>
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
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>
Paweł Gronowski
dependabot[bot]
Sebastiaan van Stijn
Sebastiaan van Stijn
Derek Misler
Docker Agent
Paulchen