{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:simplesamlphp:simplesamlphp:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "2.4.7"
              },
              {
                "introduced": "2.5.0"
              },
              {
                "fixed": "2.5.2"
              }
            ],
            "source": [
              "CPE_RANGE",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8b871fab276d4b0b2a09a727ceaa10ca3abd5d30"
            },
            {
              "introduced": "a21e4f6bd67e41c6bc5ef2b69e1cd1ed42f41e28"
            },
            {
              "fixed": "e04c29a772769bb0bacba0ba072b599779d158c4"
            }
          ],
          "repo": "https://github.com/simplesamlphp/simplesamlphp",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-q8r6-xj3f-wrrm"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-345"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49284.json"
  },
  "details": "SimpleSAMLphp versions before 1.18.6 contain an information disclosure vulnerability. Prior to 2.4.7 and 2.5.2, SimpleSAMLphp's SAML SP ACS path does not enforce the IdP selected for an SP-initiated login when unsigned Response/InResponseTo is combined with a signed assertion lacking SubjectConfirmationData/InResponseTo, allowing a response issued by one trusted IdP to be bound to SP state created for another IdP and bypass flows that route users to a specific IdP, including deployments that set enable_unsolicited to false. This issue is fixed in versions 2.4.7 and 2.5.2.",
  "id": "CVE-2026-49284",
  "modified": "2026-08-12T03:51:19.133282010Z",
  "published": "2026-07-17T19:17:23.897Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/simplesamlphp/simplesamlphp/releases/tag/v2.4.7"
    },
    {
      "type": "WEB",
      "url": "https://github.com/simplesamlphp/simplesamlphp/releases/tag/v2.5.2"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49284.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/simplesamlphp/simplesamlphp/security/advisories/GHSA-q8r6-xj3f-wrrm"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-49284"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "SimpleSAMLphp SP accepts a response from an unexpected IdP when unsigned `Response/InResponseTo` is combined with a signed assertion lacking `SubjectConfirmationData/InResponseTo`"
}