GHSA-89gr-r52h-f8rxCriticalCVSS 9.1

golang.org/x/crypto/ssh: FIDO/U2F security key physical presence check can be bypassed

Published
June 25, 2026
Last Modified
June 25, 2026

🔗 CVE IDs covered (1)

CVE-2026-39831 →

📋 Description

The Verify() method for FIDO/U2F security key types ([email protected], [email protected]) 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.

🎯 Affected products1

  • go/golang.org/x/crypto/ssh:< 0.52.0

🔗 References (6)