Description
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.
Affected products
simplesamlphp: simplesamlphp
References3
- github.com/simplesamlphp/simplesamlphp/security/advisories/GHSA… Vendor Advisory
- github.com/simplesamlphp/simplesamlphp/releases/tag/v2.4.7 ProductRelease Notes
- github.com/simplesamlphp/simplesamlphp/releases/tag/v2.5.2 ProductRelease Notes
Metrics
- CVSS 3.1
-
7.1
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N - EPSS — exploit probability
- 0% percentile: 13 · as of 14 November 2026
- CWE
- CWE-345
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