๐Ÿ” CVE Alert

CVE-2026-41670

HIGH 8.2

Admidio: SAML Response Sent to Unvalidated Assertion Consumer Service URL from AuthnRequest

CVSS Score
8.2
EPSS Score
0.0%
EPSS Percentile
0th

Admidio is an open-source user management solution. Prior to version 5.0.9, the SAML IdP implementation in Admidio's SSO module uses the AssertionConsumerServiceURL value directly from incoming SAML AuthnRequest messages as the destination for the SAML response, without validating it against the registered ACS URL (smc_acs_url) stored in the database for the corresponding service provider client. An attacker who knows the Entity ID of a registered SP client can craft a SAML AuthnRequest with an arbitrary AssertionConsumerServiceURL, causing the IdP to send the signed SAML response -- containing user identity attributes (login name, email, roles, profile fields) -- to an attacker-controlled URL. This issue has been patched in version 5.0.9.

CWE CWE-20 CWE-601
Vendor admidio
Product admidio
Published May 7, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
High
Integrity
Low
Availability
None

Affected Versions

Admidio / admidio
< 5.0.9

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
github.com: https://github.com/Admidio/admidio/security/advisories/GHSA-p9w9-87c8-m235 github.com: https://github.com/Admidio/admidio/releases/tag/v5.0.9