CVE-2026-39831
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.
- Golang Crypto
- < 0.52.0
- Fix
- Available
- CVSS 3.1
- 9.1 CRITICAL
- EPSS
- 0.4% (35th percentile)
- Weakness
- CWE-862
- NVD status
- Analyzed
- Published
- 2026-05-22
CVE-2026-39831 at NVD
No indexed exploits for CVE-2026-39831 yet
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No exploit for CVE-2026-39831 has been indexed yet. Our index is built from live traffic and upstream syncs, so this page can only say what it knows — not that no exploit exists.