CVE-2026-39831

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.

CVSS v3 9.1 CRITICAL

9.1^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://go.dev/cl/781662	Issue Tracking
https://go.dev/issue/79566	Issue Tracking
https://groups.google.com/g/golang-announce/c/a082jnz-LvI	Mailing List
https://pkg.go.dev/vuln/GO-2026-5019	Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:golang:crypto:*:*:*:*:*:go:*:*

History

No history.

Information

Published : 2026-05-22 04:16

Updated : 2026-07-23 16:10

NVD link : CVE-2026-39831

Mitre link : CVE-2026-39831

CVE.ORG link : CVE-2026-39831

JSON object : View

Products Affected

golang

crypto

CWE

CWE-862

Missing Authorization

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