Summary
social-auth-core has an Improper Authentication issue
Workarounds
Applications that cannot upgrade immediately should disable SAML account association for already authenticated users.
If SAML login is not required, the SAML backend can also be disabled by removing it from SOCIAL_AUTH_AUTHENTICATION_BACKENDS.
There is no complete workaround while continuing to allow vulnerable SAML account association.
Credits
Reported through GitHub private vulnerability reporting by Liyi Zhou, Ziyue Wang, Strick, Maurice, and Chenchen Yu from the University of Sydney security research team.
Reporter references:
Impact
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 application does not adequately verify the identity of a user, device, or process before granting access. Typical impact: unauthorized access to functions or data reserved for authenticated parties.
CVE-2026-57175 has a CVSS score of 6.4 (Medium). The vector is network-reachable, low privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (5.0.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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The issue has been fixed by validating SAML responses against stored AuthnRequest IDs.
Users should upgrade to a patched version.
Fix:
Frequently Asked Questions
- What is CVE-2026-57175? CVE-2026-57175 is a medium-severity improper authentication vulnerability in social-auth-core (pip), affecting versions < 5.0.0. It is fixed in 5.0.0. The application does not adequately verify the identity of a user, device, or process before granting access.
- How severe is CVE-2026-57175? CVE-2026-57175 has a CVSS score of 6.4 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of social-auth-core are affected by CVE-2026-57175? social-auth-core (pip) versions < 5.0.0 is affected.
- Is there a fix for CVE-2026-57175? Yes. CVE-2026-57175 is fixed in 5.0.0. Upgrade to this version or later.
- Is CVE-2026-57175 exploitable, and should I be worried? Whether CVE-2026-57175 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-57175 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-57175? Upgrade
social-auth-coreto 5.0.0 or later.