{
    "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"
                }
            }
        ]
    }
}