CVE-2026-39831

EUVD-2026-31395
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
UNKNOWN
---
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: 1%
Debian logo
Debian Releases
Debian Product
Codename
golang-go.crypto
bookworm
vulnerable
bullseye
vulnerable
forky
vulnerable
sid
vulnerable
trixie
vulnerable
Vulnerability Media Exposure
References
https://go.dev/cl/781662
https://go.dev/issue/79566
https://groups.google.com/g/golang-announce/c/a082jnz-LvI
https://pkg.go.dev/vuln/GO-2026-5019