CVE-2026-49289
No exploitation reported by the sources we read.
- Published2026-08-19
- Fixed in4.20.3 · 4.19.3
- WeaknessCWE-400
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
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.
Timeline
dates in UTC- 2026-08-1915:17CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 21:37 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-49289?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-49289?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
OSV| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 4.20 | ≥ 4.20.0, < 4.20.3 | 4.20.3 | OSV |
| 4.19 | < 4.19.3 | 4.19.3 | OSV |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 4.20 | ≥ 4.20.0, < 4.20.3 | 4.20.3 | OSV |
| 4.19 | < 4.19.3 | 4.19.3 | OSV |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
- Update simplesamlphp/saml2 to 4.20.3 · 4.19.3
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Published
- 2026-08-19
- Last Modified
- 2026-09-18
- NVD status
- Deferred
Frequently asked questions
What is CVE-2026-49289?
Is CVE-2026-49289 actively exploited?
What is the CVSS score for CVE-2026-49289?
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