CVE-2026-57175

Name	CVE-2026-57175
Description	Python Social Auth is a social authentication/registration mechanism. Prior to version 5.0.0, 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. The issue has been fixed in version 5.0.0 by validating SAML responses against stored `AuthnRequest` IDs.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
social-auth-core (PTS)	bookworm	4.3.0-1	vulnerable
	trixie	4.6.1-1	vulnerable
	forky, sid	5.1.1-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
social-auth-core	source	(unstable)	5.0.2-1

Notes

https://github.com/python-social-auth/social-core/security/advisories/GHSA-vq6g-g6c7-5f2j
https://github.com/python-social-auth/social-core/pull/1794
Fixed by: https://github.com/python-social-auth/social-core/commit/5c72f71125bc60e4411f09e2a9f998de5da7fcb6 (5.0.0)