CVSS 3.1
9.1 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NCVE-2026-39831
Critical (9.1) in golang crypto. EPSS 0.5% chance of exploitation in the next 30 days. Fixed in golang.org/x/crypto 0.52.0.
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.
Severity
- EPSS
- 0.5% chance of exploitation in the next 30 days; higher than 41% of CVEs (scores of 2026-10-31)
- CWE
- CWE-862
- Published
- Modified
- Record from
- the NVD, synced
Affected
- golang:crypto
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-89gr-r52h-f8rx | Go | golang.org/x/crypto | <0.52.0 | 0.52.0 |
| GO-2026-5019 | Go | golang.org/x/crypto | <0.52.0 | 0.52.0 |