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.
{
"unresolved_ranges": [
{
"source": "AFFECTED_FIELD",
"extracted_events": [
{
"fixed": "0.52.0"
}
]
}
],
"cna_assigner": "Go",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39831.json"
}{
"source": "CPE_RANGE",
"cpe": "cpe:2.3:a:golang:crypto:*:*:*:*:*:go:*:*",
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "0.52.0"
}
]
}