CVE-2026-39831
Critical
Description
The Verify() method for FIDO/U2F security key types ([email protected], [email protected]) 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.
SeverityCritical
CVSS9.1
Exploit probability—
Product
Golang Crypto
PublishedMay 22, 2026
First seenMay 22, 2026
Weakness typeCWE-290CWE-290
How to fix
Update
- golang crypto0.52.0 or later
- golang.org/x/crypto0.52.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| golang crypto | v < 0.52.0 | 0.52.0 |
| golang.org/x/cryptoGo | v < 0.52.0 | 0.52.0 |
| microsoft azl3_kubevirt-openvmm_1.9.0-1 | No range specified | — |
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