This releases includes 6 security fixes following the security policy: - archive/zip: denial of service when parsing arbitrary ZIP archives archive/zip used a super-linear file name indexing algorithm that is invoked the first time a file in an archive is opened. This can lead to a denial of service when consuming a maliciously constructed ZIP archive. Thanks to Thanks to Jakub Ciolek for reporting this issue. This is CVE-2025-61728 and Go issue https://go.dev/issue/77102. - net/http: memory exhaustion in Request.ParseForm When parsing a URL-encoded form net/http may allocate an unexpected amount of memory when provided a large number of key-value pairs. This can result in a denial of service due to memory exhaustion. Thanks to jub0bs for reporting this issue. This is CVE-2025-61726 and Go issue https://go.dev/issue/77101. - crypto/tls: Config.Clone copies automatically generated session ticket keys, session resumption does not account for the expiration of full certificate chain The Config.Clone methods allows cloning a Config which has already been passed to a TLS function, allowing it to be mutated and reused. If Config.SessionTicketKey has not been set, and Config.SetSessionTicketKeys has not been called, crypto/tls will generate random session ticket keys and automatically rotate them. Config.Clone would copy these automatically generated keys into the returned Config, meaning that the two Configs would share session ticket keys, allowing sessions created using one Config could be used to resume sessions with the other Config. This can allow clients to resume sessions even though the Config may be configured such that they should not be able to do so. Config.Clone no longer copies the automatically generated session ticket keys. Config.Clone still copies keys which are explicitly provided, either by setting Config.SessionTicketKey or by calling Config.SetSessionTicketKeys. This issue was discoverd by the Go Security team while investigating another issue reported by Coia Prant (github.com/rbqvq). Additionally, on the server side only the expiration of the leaf certificate, if one was provided during the initial handshake, was checked when considering if a session could be resumed. This allowed sessions to be resumed if an intermediate or root certificate in the chain had expired. Session resumption now takes into account of the full chain when determining if the session can be resumed. Thanks to Coia Prant (github.com/rbqvq) for reporting this issue. This is CVE-2025-68121 and Go issue https://go.dev/issue/77113. - cmd/go: bypass of flag sanitization can lead to arbitrary code execution Usage of 'CgoPkgConfig' allowed execution of the pkg-config binary with flags that are not explicitly safe-listed. To prevent this behavior, compiler flags resulting from usage of 'CgoPkgConfig' are sanitized prior to invoking pkg-config. Thank you to RyotaK (https://ryotak.net) of GMO Flatt Security Inc. for reporting this issue. This is CVE-2025-61731 and go.dev/issue/77100. - cmd/go: unexpected code execution when invoking toolchain The Go toolchain supports multiple VCS which are used retrieving modules and embedding build information into binaries. On systems with Mercurial installed (hg) downloading modules (e.g. via go get or go mod download) from non-standard sources (e.g. custom domains) can cause unexpected code execution due to how external VCS commands are constructed. On systems with Git installed, downloading and building modules with malicious version strings could allow an attacker to write to arbitrary files on the system the user has access to. This can only be triggered by explicitly providing the malicious version strings to the toolchain, and does not affect usage of @latest or bare module paths. The toolchain now uses safer VCS options to prevent misinterpretation of untrusted inputs. In addition, the toolchain now disallows module version strings prefixed with a "-" or "/" character. Thanks to splitline (@splitline) from DEVCORE Research Team for reporting this issue. This is CVE-2025-68119 and Go issue https://go.dev/issue/77099. - crypto/tls: handshake messages may be processed at the incorrect encryption level During the TLS 1.3 handshake if multiple messages are sent in records that span encryption level boundaries (for instance the Client Hello and Encrypted Extensions messages), the subsequent messages may be processed before the encryption level changes. This can cause some minor information disclosure if a network-local attacker can inject messages during the handshake. Thanks to Coia Prant (github.com/rbqvq) for reporting this issue. This is CVE-2025-61730 and Go issue https://go.dev/issue/76443 View the release notes for more information: https://go.dev/doc/devel/release#go1.25.6 Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>

Commits

Commits on Jan 16, 2026

update to go1.25.6