Vulnerability in Simplesamlphp
CVE-2026-49284
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N.
EPSS exploit prediction
EPSS: 0.002 (11.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 12th percentile — 11.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
- Simplesamlphp — versions < 2.4.7, >= 2.5.0-rc1, < 2.5.2
Weakness classification (CWE)
References
- github.com/simplesamlphp/simplesamlphp/security/advisories/GHSA-q8r6-xj3f-wrrm (Vendor Advisory)
- github.com/simplesamlphp/simplesamlphp/releases/tag/v2.4.7 (Product, Release Notes)
- github.com/simplesamlphp/simplesamlphp/releases/tag/v2.5.2 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-49284?
- CVE-2026-49284 is a high-severity vulnerability in Simplesamlphp, classified under Insufficient Verification of Data Authenticity. CVSS score: 7.1/10. Published 2026-07-17.
- How severe is CVE-2026-49284?
- High severity. CVSS v3 base score is 7.1 out of 10.