CyberRota Analysis
This is a critical severity vulnerability with a CVSS score of 9.1. See the original NVD description below for full technical details.
CVE
CVE-2026-39831
Severity
CRITICAL
CVSS
9.1
EPSS
0.42%
Original NVD 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.
Related CVEs
Other vulnerabilities affecting the same vendor(s)