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.

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-5cjr-mxj5-wmrx SimpleSAMLphp has Possible DoS via XPath Transform
Fixes

Solution

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Workaround

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History

Wed, 19 Aug 2026 18:00:00 +0000

Type Values Removed Values Added
First Time appeared Simplesamlphp
Simplesamlphp saml2
Vendors & Products Simplesamlphp
Simplesamlphp saml2

Wed, 19 Aug 2026 15:00:00 +0000

Type Values Removed Values Added
Description 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.
Title SimpleSAMLphp SAML2: Possible DoS via XPath Transform
Weaknesses CWE-400
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-19T18:04:15.406Z

Reserved: 2026-05-28T20:07:58.862Z

Link: CVE-2026-49289

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-19T15:17:07.180

Modified: 2026-08-19T18:16:41.317

Link: CVE-2026-49289

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-19T17:45:03Z

Weaknesses