{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-49283", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-05-28T20:07:58.861Z", "datePublished": "2026-08-19T14:47:05.519Z", "dateUpdated": "2026-08-19T18:19:10.978Z"}, "containers": {"cna": {"title": "SimpleSAMLphp HTTP-Artifact TLS validator confusion allows cross-IdP authentication bypass", "problemTypes": [{"descriptions": [{"cweId": "CWE-295", "lang": "en", "description": "CWE-295: Improper Certificate Validation", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 8.7, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "HIGH", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N", "version": "3.1"}}], "references": [{"name": "https://github.com/simplesamlphp/saml2/security/advisories/GHSA-6929-8p9f-26jx", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/simplesamlphp/saml2/security/advisories/GHSA-6929-8p9f-26jx"}, {"name": "https://github.com/simplesamlphp/saml2/commit/4a71b20d8d845579fd0a54d6449c265b40db459d", "tags": ["x_refsource_MISC"], "url": "https://github.com/simplesamlphp/saml2/commit/4a71b20d8d845579fd0a54d6449c265b40db459d"}, {"name": "https://github.com/simplesamlphp/saml2/commit/a2c1ac588c70d7b7998546cf32675fb113f22a5f", "tags": ["x_refsource_MISC"], "url": "https://github.com/simplesamlphp/saml2/commit/a2c1ac588c70d7b7998546cf32675fb113f22a5f"}, {"name": "https://github.com/simplesamlphp/saml2/commit/d5c213132ef671c0018a11252322034dbddd735a", "tags": ["x_refsource_MISC"], "url": "https://github.com/simplesamlphp/saml2/commit/d5c213132ef671c0018a11252322034dbddd735a"}, {"name": "https://github.com/simplesamlphp/saml2/commit/e2df7992609964951b2a3e7d6566b7427b2a968f", "tags": ["x_refsource_MISC"], "url": "https://github.com/simplesamlphp/saml2/commit/e2df7992609964951b2a3e7d6566b7427b2a968f"}], "affected": [{"vendor": "simplesamlphp", "product": "saml2", "versions": [{"version": "< 4.19.3", "status": "affected"}, {"version": ">= 4.20.0, < 4.20.2", "status": "affected"}, {"version": ">= 5.0.0, < 5.0.6", "status": "affected"}, {"version": ">= 6.0.0, < 6.2.1", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-08-19T14:47:05.519Z"}, "descriptions": [{"lang": "en", "value": "The SimpleSAMLphp SAML2 library is a PHP library for SAML2 related functionality. Prior to versions 4.19.3, 4.20.2, 5.0.6, and 6.2.1, the HTTPArtifact::receive() flow can treat an unsigned embedded SAML Response as cryptographically valid for the wrong identity provider. SOAPClient::addSSLValidator() attaches a TLS-based validator to the outer SOAP ArtifactResponse, while the embedded Response receives a validator that delegates to the outer message and is later checked against metadata selected from the embedded response issuer rather than necessarily the artifact issuer. SOAPClient::validateSSL() returns normally when the TLS public key does not match the key being validated, and SAML2\\Message::validate() treats a validator call that does not throw as successful. In a multi-IdP federation, a malicious or lower-trust IdP can therefore provide an ArtifactResponse containing an unsigned Response that claims a higher-trust victim IdP as issuer and authenticate as arbitrary users with attacker-chosen assertion attributes, NameID, and session data. This issue is fixed in versions 4.19.3, 4.20.2, 5.0.6, and 6.2.1."}], "source": {"advisory": "GHSA-6929-8p9f-26jx", "discovery": "UNKNOWN"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-08-19T18:16:10.690773Z", "id": "CVE-2026-49283", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"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": "2026-08-19T18:19:10.978Z"}}]}}

{}

{"affected": [{"affectedData": [{"product": "saml2", "vendor": "simplesamlphp", "versions": [{"status": "affected", "version": "< 4.19.3"}, {"status": "affected", "version": ">= 4.20.0, < 4.20.2"}, {"status": "affected", "version": ">= 5.0.0, < 5.0.6"}, {"status": "affected", "version": ">= 6.0.0, < 6.2.1"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "The SimpleSAMLphp SAML2 library is a PHP library for SAML2 related functionality. Prior to versions 4.19.3, 4.20.2, 5.0.6, and 6.2.1, the HTTPArtifact::receive() flow can treat an unsigned embedded SAML Response as cryptographically valid for the wrong identity provider. SOAPClient::addSSLValidator() attaches a TLS-based validator to the outer SOAP ArtifactResponse, while the embedded Response receives a validator that delegates to the outer message and is later checked against metadata selected from the embedded response issuer rather than necessarily the artifact issuer. SOAPClient::validateSSL() returns normally when the TLS public key does not match the key being validated, and SAML2\\Message::validate() treats a validator call that does not throw as successful. In a multi-IdP federation, a malicious or lower-trust IdP can therefore provide an ArtifactResponse containing an unsigned Response that claims a higher-trust victim IdP as issuer and authenticate as arbitrary users with attacker-chosen assertion attributes, NameID, and session data. This issue is fixed in versions 4.19.3, 4.20.2, 5.0.6, and 6.2.1."}], "id": "CVE-2026-49283", "lastModified": "2026-08-19T15:17:07.027", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 8.7, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "HIGH", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 2.3, "impactScore": 5.8, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-08-19T15:17:07.027", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/simplesamlphp/saml2/commit/4a71b20d8d845579fd0a54d6449c265b40db459d"}, {"source": "security-advisories@github.com", "url": "https://github.com/simplesamlphp/saml2/commit/a2c1ac588c70d7b7998546cf32675fb113f22a5f"}, {"source": "security-advisories@github.com", "url": "https://github.com/simplesamlphp/saml2/commit/d5c213132ef671c0018a11252322034dbddd735a"}, {"source": "security-advisories@github.com", "url": "https://github.com/simplesamlphp/saml2/commit/e2df7992609964951b2a3e7d6566b7427b2a968f"}, {"source": "security-advisories@github.com", "url": "https://github.com/simplesamlphp/saml2/security/advisories/GHSA-6929-8p9f-26jx"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-295"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,4.19.3)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[4.20.0,4.20.2)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[5.0.0,5.0.6)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.0.0,6.2.1)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "saml2", "source": "cna", "vendor": "simplesamlphp"}, "product": "saml2", "vendor": "simplesamlphp"}], "created": "2026-08-19T17:45:03.123820+00:00", "updated": "2026-08-19T18:00:05.929477+00:00", "vendors": ["simplesamlphp", "simplesamlphp$PRODUCT$saml2"]}