Improper Certificate Validation Affecting simplesamlphp/saml2-legacy package, versions <4.20.2
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-PHP-SIMPLESAMLPHPSAML2LEGACY-17798866
- published2 Jul 2026
- disclosed2 Jul 2026
- creditUnknown
Introduced: 2 Jul 2026
CVE-2026-49283 (opens in a new tab)How to fix?
Upgrade simplesamlphp/saml2-legacy to version 4.20.2 or higher.
Overview
Affected versions of this package are vulnerable to Improper Certificate Validation in the HTTPArtifact::receive process. An attacker can gain unauthorized access to arbitrary user accounts by crafting a forged unsigned assertion from a malicious or lower-trust identity provider within the same federation. This is only exploitable if a multi-IdP or federation deployment is used and a malicious or lower-trust IdP can issue HTTP-Artifact responses to the service provider.