Input validation error in Admidio - CVE-2026-41670
Published: April 23, 2026
Vulnerability identifier: #VU127171
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-41670
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Admidio
Affected software:
Admidio
Admidio
Detailed vulnerability description
The vulnerability allows a remote attacker to disclose sensitive information and impersonate a user at a service provider.
The vulnerability exists due to improper input validation in the SAML IdP implementation in src/SSO/Service/SAMLService.php when processing SAML AuthnRequest messages. A remote attacker can send a crafted AuthnRequest with an attacker-controlled AssertionConsumerServiceURL to disclose sensitive information and impersonate a user at a service provider.
User interaction is required, and exploitation is possible without signature verification when the service provider client uses the default settings for request signing validation.
How to mitigate CVE-2026-41670
Install security update from vendor's website.