CVE-2026-39831

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{"affected": [{"affectedData": [{"collectionURL": "https://pkg.go.dev", "defaultStatus": "unaffected", "packageName": "golang.org/x/crypto/ssh", "product": "golang.org/x/crypto/ssh", "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"}], "vendor": "golang.org/x/crypto", "versions": [{"lessThan": "0.52.0", "status": "affected", "version": "0", "versionType": "semver"}]}], "source": "security@golang.org"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:golang:crypto:*:*:*:*:*:go:*:*", "matchCriteriaId": "D540395B-31B8-4B07-8F79-F5C631BBD5C8", "versionEndExcluding": "0.52.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "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."}, {"lang": "es", "value": "El m\u00e9todo Verify() para tipos de clave de seguridad FIDO/U2F (sk-ecdsa-sha2-nistp256@openssh.com, sk-ssh-ed25519@openssh.com) no verificaba el indicador de Presencia de Usuario. Se aceptaban firmas generadas sin contacto f\u00edsico, lo que permit\u00eda el uso desatendido de una clave de seguridad de hardware. Para restaurar el comportamiento anterior, devuelva una extensi\u00f3n 'no-touch-required' en Permissions.Extensions desde PublicKeyCallback."}], "id": "CVE-2026-39831", "lastModified": "2026-07-23T16:10:00.137", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 9.1, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.2, "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-39831", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-05-22T18:51:41.233749Z", "version": "2.0.3"}}]}, "published": "2026-05-22T04:16:22.553", "references": [{"source": "security@golang.org", "tags": ["Issue Tracking"], "url": "https://go.dev/cl/781662"}, {"source": "security@golang.org", "tags": ["Issue Tracking"], "url": "https://go.dev/issue/79566"}, {"source": "security@golang.org", "tags": ["Mailing List"], "url": "https://groups.google.com/g/golang-announce/c/a082jnz-LvI"}, {"source": "security@golang.org", "tags": ["Vendor Advisory"], "url": "https://pkg.go.dev/vuln/GO-2026-5019"}], "sourceIdentifier": "security@golang.org", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-862"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{}

{"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": "2026-06-02T20:00:13.503734+00:00", "vendors": ["golang", "golang$PRODUCT$ssh"]}