{"api_version":"1","generated_at":"2026-06-02T02:46:36+00:00","cve":"CVE-2026-39831","urls":{"html":"https://cve.report/CVE-2026-39831","api":"https://cve.report/api/cve/CVE-2026-39831.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-39831","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-39831"},"summary":{"title":"Invoking  bypass of FIDO/U2F security keys physical interaction in golang.org/x/crypto/ssh","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. 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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."}],"problemTypes":[{"descriptions":[{"description":"CWE-290: Authentication Bypass by Spoofing","lang":"en"}]}],"providerMetadata":{"dateUpdated":"2026-05-22T02:31:27.436Z","orgId":"1bb62c36-49e3-4200-9d77-64a1400537cc","shortName":"Go"},"references":[{"url":"https://go.dev/issue/79566"},{"url":"https://groups.google.com/g/golang-announce/c/a082jnz-LvI"},{"url":"https://go.dev/cl/781662"},{"url":"https://pkg.go.dev/vuln/GO-2026-5019"}],"title":"Invoking  bypass of FIDO/U2F security keys physical interaction in golang.org/x/crypto/ssh"}},"cveMetadata":{"assignerOrgId":"1bb62c36-49e3-4200-9d77-64a1400537cc","assignerShortName":"Go","cveId":"CVE-2026-39831","datePublished":"2026-05-22T02:31:27.436Z","dateReserved":"2026-04-07T18:13:03.528Z","dateUpdated":"2026-05-22T18:52:08.344Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-22 04:16:22","lastModifiedDate":"2026-05-22 04:16:22","problem_types":["CWE-290: Authentication Bypass by Spoofing"],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"39831","Ordinal":"1","Title":"Invoking  bypass of FIDO/U2F security keys physical interaction ","CVE":"CVE-2026-39831","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"39831","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"Invoking  bypass of FIDO/U2F security keys physical interaction "}]}}}