critical

CVE-2026-39832

Go · golang.org/x/crypto/ssh/agent • Go · golang.org/x/crypto

Summary

golang.org/x/crypto/ssh/agent doesn't drop invoking agent constraints when forwarding keys

Severity
critical
CVSS
9.1
EPSS
0.6% (p47)
CWE
CWE-502
Also known as
GHSA-f5wc-c3c7-36mc, GO-2026-5006
Published
2026-06-25
Updated
2026-06-25

Advisory details

When adding a key to a remote agent constraint extensions such as restrict-destination-v00@openssh.com were not serialized in the request. Destination restrictions were silently stripped when forwarding keys, allowing unrestricted use of the key on the remote host. The client now serializes all constraint extensions. Additionally, the in-memory keyring returned by NewKeyring() now rejects keys with unsupported constraint extensions instead of silently ignoring them.

References

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Sources: CISA KEV (public domain), OSV.dev & GitHub Advisory Database (CC-BY-4.0), FIRST EPSS, NVD/CWE (public domain). Served live from the Stateward advisory database.