{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-39831", "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc", "state": "PUBLISHED", "assignerShortName": "Go", "dateReserved": "2026-04-07T18:13:03.528Z", "datePublished": "2026-05-22T02:31:27.436Z", "dateUpdated": "2026-05-22T18:52:08.344Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc", "shortName": "Go", "dateUpdated": "2026-05-22T02:31:27.436Z"}, "title": "Invoking bypass of FIDO/U2F security keys physical interaction in golang.org/x/crypto/ssh", "descriptions": [{"lang": "en", "value": "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."}], "affected": [{"vendor": "golang.org/x/crypto", "product": "golang.org/x/crypto/ssh", "collectionURL": "https://pkg.go.dev", "packageName": "golang.org/x/crypto/ssh", "versions": [{"version": "0", "lessThan": "0.52.0", "status": "affected", "versionType": "semver"}], "programRoutines": [{"name": "CertChecker.CheckCert"}, {"name": "skECDSAPublicKey.Verify"}, {"name": "skEd25519PublicKey.Verify"}, {"name": "connection.serverAuthenticate"}, {"name": "CertChecker.Authenticate"}, {"name": "CertChecker.CheckHostKey"}, {"name": "Certificate.Verify"}, {"name": "Dial"}, {"name": "NewClientConn"}, {"name": "NewServerConn"}], "defaultStatus": "unaffected"}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "CWE-290: Authentication Bypass by Spoofing"}]}], "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"}], "credits": [{"lang": "en", "value": "NCC Group Cryptography Services, sponsored by Teleport"}]}, "adp": [{"metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.1, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}}, {"other": {"type": "ssvc", "content": {"timestamp": "2026-05-22T18:51:41.233749Z", "id": "CVE-2026-39831", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-05-22T18:52:08.344Z"}}]}}

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{"cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-39831", "lastModified": "2026-05-22T04:16:22.553", "metrics": {}, "published": "2026-05-22T04:16:22.553", "references": [{"source": "security@golang.org", "url": "https://go.dev/cl/781662"}, {"source": "security@golang.org", "url": "https://go.dev/issue/79566"}, {"source": "security@golang.org", "url": "https://groups.google.com/g/golang-announce/c/a082jnz-LvI"}, {"source": "security@golang.org", "url": "https://pkg.go.dev/vuln/GO-2026-5019"}], "sourceIdentifier": "security@golang.org", "vulnStatus": "Received"}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,0.52.0)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "manual", "scores": [{"score": 100.0, "source": "manual"}]}, "original": {"product": "golang.org/x/crypto/ssh", "source": "cna", "vendor": "golang.org/x/crypto"}, "product": "ssh", "vendor": "golang"}], "created": "2026-05-22T04:30:25.964671+00:00", "updated": "2026-05-22T21:00:12.705625+00:00", "vendors": ["golang", "golang$PRODUCT$ssh"]}