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.
Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-p9w9-87c8-m235 | Admidio Sends SAML Response to Unvalidated Assertion Consumer Service URL from AuthnRequest |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 07 May 2026 05:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Admidio
Admidio admidio |
|
| Vendors & Products |
Admidio
Admidio admidio |
Thu, 07 May 2026 04:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | Admidio: SAML Response Sent to Unvalidated Assertion Consumer Service URL from AuthnRequest | |
| Weaknesses | CWE-20 CWE-601 |
|
| References |
| |
| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-05-07T03:00:39.851Z
Reserved: 2026-04-22T03:53:24.405Z
Link: CVE-2026-41670
No data.
Status : Received
Published: 2026-05-07T04:16:30.993
Modified: 2026-05-07T04:16:30.993
Link: CVE-2026-41670
No data.
OpenCVE Enrichment
Updated: 2026-05-07T05:45:06Z
Github GHSA