CVE-2026-39831

9.1 CRITICAL
Published: May 22, 2026 Modified: June 02, 2026
View on 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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://go.dev/cl/781662
Source: security@golang.org
Issue Tracking
https://go.dev/issue/79566
Source: security@golang.org
Issue Tracking
https://groups.google.com/g/golang-announce/c/a082jnz-LvI
Source: security@golang.org
Mailing List
https://pkg.go.dev/vuln/GO-2026-5019
Source: security@golang.org
Vendor Advisory

4 reference(s) from NVD

Quick Stats

CVSS v3 Score
9.1 / 10.0
EPSS (Exploit Probability)
0.0%
10th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

golang