Summary
social-auth-core Vulnerable to Account Takeover via Identity Binding Flaw in Vend Backend
Workarounds
Applications that cannot upgrade immediately should restrict the Vend OAuth2 backend to a single trusted Vend shop.
If Vend authentication is not required, the Vend backend can also be disabled by removing it from SOCIAL_AUTH_AUTHENTICATION_BACKENDS.
There is no complete workaround while continuing to allow authentication from multiple Vend shops with the vulnerable backend.
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 Vend OAuth2 backend used only the numeric Vend user_id as the social-auth UID.
When multiple Vend shops authenticate through the same application, users from different shops with the same internal Vend user ID could collide in the social-auth association table. A user from one shop could then be authenticated as the local account previously associated with the same numeric user ID from another shop.
The issue affects applications using the Vend OAuth2 backend with more than one Vend shop.
CVE-2026-57176 has a CVSS score of 6.8 (Medium). The vector is network-reachable, low privileges required, and no user interaction. 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 scoping Vend social-auth UIDs by shop.
Users should upgrade to a patched version.
Fix:
Frequently Asked Questions
- What is CVE-2026-57176? CVE-2026-57176 is a medium-severity security vulnerability in social-auth-core (pip), affecting versions < 5.0.0. It is fixed in 5.0.0.
- How severe is CVE-2026-57176? CVE-2026-57176 has a CVSS score of 6.8 (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-2026-57176? social-auth-core (pip) versions < 5.0.0 is affected.
- Is there a fix for CVE-2026-57176? Yes. CVE-2026-57176 is fixed in 5.0.0. Upgrade to this version or later.
- Is CVE-2026-57176 exploitable, and should I be worried? Whether CVE-2026-57176 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-2026-57176 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-2026-57176? Upgrade
social-auth-coreto 5.0.0 or later.