Improper Certificate Validation Affecting simplesamlphp package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DEBIAN14-SIMPLESAMLPHP-19229326
- published23 Aug 2026
- disclosed19 Aug 2026
Introduced: 19 Aug 2026
CVE-2026-49283 (opens in a new tab)How to fix?
There is no fixed version for Debian:14 simplesamlphp.
NVD Description
Note: Versions mentioned in the description apply only to the upstream simplesamlphp package and not the simplesamlphp package as distributed by Debian.
See How to fix? for Debian:14 relevant fixed versions and status.
The SimpleSAMLphp SAML2 library is a PHP library for SAML2 related functionality. Prior to versions 4.19.3, 4.20.2, 5.0.6, and 6.2.1, the HTTPArtifact::receive() flow can treat an unsigned embedded SAML Response as cryptographically valid for the wrong identity provider. SOAPClient::addSSLValidator() attaches a TLS-based validator to the outer SOAP ArtifactResponse, while the embedded Response receives a validator that delegates to the outer message and is later checked against metadata selected from the embedded response issuer rather than necessarily the artifact issuer. SOAPClient::validateSSL() returns normally when the TLS public key does not match the key being validated, and SAML2\Message::validate() treats a validator call that does not throw as successful. In a multi-IdP federation, a malicious or lower-trust IdP can therefore provide an ArtifactResponse containing an unsigned Response that claims a higher-trust victim IdP as issuer and authenticate as arbitrary users with attacker-chosen assertion attributes, NameID, and session data. This issue is fixed in versions 4.19.3, 4.20.2, 5.0.6, and 6.2.1.
References
- https://security-tracker.debian.org/tracker/CVE-2026-49283
- https://github.com/simplesamlphp/saml2/commit/4a71b20d8d845579fd0a54d6449c265b40db459d
- https://github.com/simplesamlphp/saml2/commit/a2c1ac588c70d7b7998546cf32675fb113f22a5f
- https://github.com/simplesamlphp/saml2/commit/d5c213132ef671c0018a11252322034dbddd735a
- https://github.com/simplesamlphp/saml2/commit/e2df7992609964951b2a3e7d6566b7427b2a968f
- https://github.com/simplesamlphp/saml2/security/advisories/GHSA-6929-8p9f-26jx