CVE-2026-49289

HIGH 7.5

SimpleSAMLphp SAML2: Possible DoS via XPath Transform

CVSS Score

7.5

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-400
Vendor	simplesamlphp
Product	saml2
Published	Aug 19, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Affected Versions

simplesamlphp / saml2

>= 4.19.2, < 4.19.3 >= 4.20.2, < 4.20.3

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/simplesamlphp/saml2/security/advisories/GHSA-5cjr-mxj5-wmrx github.com: https://github.com/simplesamlphp/saml2/commit/0043033891fdba9618386ab583e1d8afdf8aea6e github.com: https://github.com/simplesamlphp/saml2/commit/6695eb923da491f716009c2a26b34a463ac05c6b