CVE-2026-57175: social-auth-core has an Improper Authentication issue

The SAML backend accepted SAML responses on the Assertion Consumer Service endpoint without verifying that they matched a previously issued AuthnRequest.

Applications using SAML account association could allow an attacker with a valid account on a trusted IdP to link the attacker’s SAML identity to a logged-in victim’s local account. The attacker could then authenticate through SAML and gain access to the victim’s account.

The issue affects applications using the SAML backend together with authenticated account association.