CVE-2026-39831CRITICAL 9.1EPSS p22.4%
CVE-2026-39831CVE-2026-39831
golang / crypto
Description
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.
Scoring
| CVSS 3.1 | 9.1 (CRITICAL) |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| EPSS | 0.31% probability of exploitation · percentile 22.4% · 2026-06-18T12:00:27Z |
| Published | 2026-05-22 |
| Last modified | 2026-06-02 |
References
Related by meaning· 6
Nearest entities by semantic similarity across the cs-graph corpus.