CVE-2026-49289
SimpleSAMLphp SAML2: Possible DoS via XPath Transform
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Deferred | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.78% · top 44% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Weakness
Affected products
- affected >= 4.19.2, < 4.19.3
- affected >= 4.20.2, < 4.20.3
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Packagistsimplesamlphp/saml2GHSA-5cjr-mxj5-wmrx (opens in a new tab)
- Packagistsimplesamlphp/saml2-legacyGHSA-5cjr-mxj5-wmrx (opens in a new tab)
References (3)
- https://github.com/simplesamlphp/saml2/security/advisories/GHSA-5cjr-mxj5-wmrx (opens in a new tab)x_refsource_CONFIRM
- https://github.com/simplesamlphp/saml2/commit/0043033891fdba9618386ab583e1d8afdf8aea6e (opens in a new tab)x_refsource_MISC
- https://github.com/simplesamlphp/saml2/commit/6695eb923da491f716009c2a26b34a463ac05c6b (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-5cjr-mxj5-wmrx (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-49289)Record last updated .