CVE-2026-49289
HighCVSS 7.5Summary
The SimpleSAMLphp SAML2 library in versions 4.19.2 and 4.20.2 allows attacker-controlled XPath transforms while processing XML signatures in specially crafted SAML messages. XPath evaluation can consume uncontrolled processing resources, allowing a remote unauthenticated attacker to deny service. This issue is fixed in versions 4.19.3 and 4.20.3.
Risk Assessment
The attack can cause system overload and unavailability of authentication services based on SimpleSAMLphp, impacting business continuity.
Recommendation
Immediately update the SimpleSAMLphp SAML2 library to version 4.19.3 or 4.20.3.
Original NVD description (English source)
The SimpleSAMLphp SAML2 library is a PHP library for SAML2 related functionality. In 4.19.2 and 4.20.2, the library permits attacker-controlled XPath transforms while processing XML signatures in specially crafted SAML messages. XPath evaluation can consume uncontrolled processing resources, allowing a remote unauthenticated attacker to deny service to any entity relying on SimpleSAMLphp or directly on the SAML2 library. The mitigation limits the number of transforms, permits only transform algorithms identified by the SAML 2.0 Core specification, and specifically rejects XPath transforms. This issue is fixed in versions 4.19.3 and 4.20.3.