Riskcovery

CVE-2026-49284

SimpleSAMLphp SP accepts a response from an unexpected IdP when unsigned `Response/InResponseTo` is combined with a signed assertion lacking `SubjectConfirmationData/InResponseTo`

State
Published
Severity
7.1 High
Published
Jul 17, 2026
Updated
Jul 20, 2026
Reserved
May 28, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
3.17.1 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:NGitHub_M

Weaknesses

  • CWE-345 Insufficient Verification of Data Authenticity

Affected Products

ProductVersions
simplesamlphpsimplesamlphp
  • < 2.4.7Affected
  • >= 2.5.0-rc1, < 2.5.2Affected

References

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