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.

References

https://pkg.go.dev/vuln/GO-2026-5019

https://groups.google.com/g/golang-announce/c/a082jnz-LvI

https://go.dev/issue/79566

https://go.dev/cl/781662

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-31395

Details

Source: Mitre, NVD

Published: 2026-05-22

Updated: 2026-07-23

Named Vulnerability: GO-2026-5019Named Vulnerability: GHSA-89gr-r52h-f8rx

Risk Information

CVSS v2

Base Score: 9.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:N

Severity: High

CVSS v3

Base Score: 9.1

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Severity: Critical

EPSS

EPSS: 0.00487