{"id":"CVE-2026-39831","summary":"Invoking  bypass of FIDO/U2F security keys physical interaction in golang.org/x/crypto/ssh","details":"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.","aliases":["GO-2026-5019"],"modified":"2026-06-06T18:29:54.000420287Z","published":"2026-05-22T02:31:27.436Z","related":["CGA-vmc4-96w4-wr4c","openSUSE-SU-2026:10842-1","openSUSE-SU-2026:10845-1","openSUSE-SU-2026:10856-1","openSUSE-SU-2026:10949-1","openSUSE-SU-2026:20833-1","openSUSE-SU-2026:20834-1","openSUSE-SU-2026:20838-1","openSUSE-SU-2026:20902-1"],"database_specific":{"cna_assigner":"Go","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39831.json","unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"fixed":"0.52.0"}]}]},"references":[{"type":"WEB","url":"https://go.dev/cl/781662"},{"type":"WEB","url":"https://go.dev/issue/79566"},{"type":"WEB","url":"https://groups.google.com/g/golang-announce/c/a082jnz-LvI"},{"type":"WEB","url":"https://pkg.go.dev"},{"type":"WEB","url":"https://pkg.go.dev/vuln/GO-2026-5019"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39831.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-39831"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/golang/crypto","events":[{"introduced":"0"},{"fixed":"a1c0d9929856c8aba2b31f079340f00578eda803"}],"database_specific":{"source":"CPE_RANGE","cpe":"cpe:2.3:a:golang:crypto:*:*:*:*:*:go:*:*","extracted_events":[{"introduced":"0"},{"fixed":"0.52.0"}]}}],"versions":["v0.51.0","v0.50.0","v0.49.0","v0.48.0","v0.47.0","v0.46.0","v0.45.0","v0.44.0","v0.43.0","v0.42.0","v0.41.0","v0.40.0","v0.39.0","v0.38.0","v0.37.0","v0.36.0","v0.35.0","v0.34.0","v0.33.0","v0.32.0","v0.31.0","v0.30.0","v0.29.0","v0.28.0","v0.27.0","v0.26.0","v0.25.0","v0.24.0","v0.23.0","v0.22.0","v0.21.0","v0.20.0","v0.19.0","v0.18.0","v0.17.0","v0.16.0","v0.15.0","v0.14.0","v0.13.0","v0.12.0","v0.11.0","v0.10.0","v0.9.0","v0.8.0","v0.7.0","v0.6.0","v0.5.0","v0.4.0","v0.3.0","v0.2.0","v0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-39831.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"}]}