CRITICALCVE-2026-39831Published Modified CNA Go
CVE-2026-39831: Invoking bypass of FIDO/U2F security keys physical interaction in golang.org/x/crypto/ssh
The Verify() method for FIDO/U2F security key types (sk-ecdsa-sha2-nistp256@openssh.com, sk-ssh-ed25519@openssh.com) did not check the User Presence flag. Signatures generated without physical touch were accepted, allowing unattended use of a hardware security key. To restore the previous behavior, return a "no-touch-required" extension in Permissions.Extensions from PublicKeyCallback.
Metrics
- CVSS v3.1
- 9.1
- Severity
- CRITICAL
- Fixed in
- 0.52.0
- Affected Products
- 1
Fix available
0.52.0
Affected packages
- golang.org/x/crypto / golang.org/x/crypto/ssh< 0.52.0 (from 0)
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NReferences