SimpleSAMLphp SP accepts a response from an unexpected IdP when unsigned `Response/InResponseTo` is combined with a s...

Date Jul 2, 2026
Type Vendor advisory
Signal High-risk advisory
Vendor / Product Composer ยท simplesamlphp/simplesamlphp
CVE CVE-2026-49284
High-risk advisory CVE-2026-49284

Summary

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

Why it matters

GitHub has published a reviewed security advisory for simplesamlphp/simplesamlphp. Prioritize it with other application dependency updates.

Operator check

Check whether simplesamlphp/simplesamlphp is present in application dependency manifests, lockfiles, or build images. Review the GitHub advisory and upgrade to a patched version where available.

Sources

PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.