CVE-2026-57175 python-social-auth CVE debrief

Who should care

Defenders responsible for configuring and maintaining Python Social Auth should assess exposure and verify SAML response validation. This includes reviewing account association settings for SAML backends and ensuring that the validation of SAML responses against stored AuthnRequest IDs is properly implemented. Prioritization is especially important for applications using SAML account association.

Why it matters

CVE-2026-57175 is a medium-severity vulnerability in Python Social Auth that allows an attacker to link their SAML identity to a victim's local account, potentially gaining access to the victim's account. Defenders should prioritize verifying SAML response validation in Python Social Auth configurations, especially for applications using SAML account association. The issue has been fixed in version 5.0.0.

• Potential unauthorized access to victim accounts through SAML authentication
• Need to verify SAML response validation in Python Social Auth configurations
• Possible account association vulnerabilities in applications using SAML backends

Technical summary

The Python Social Auth library did not verify SAML responses against stored AuthnRequest IDs, allowing an attacker to link their SAML identity to a victim's local account. This issue enables an attacker with a valid account on a trusted IdP to authenticate through SAML and gain access to the victim's account if the application uses SAML account association. The fix in version 5.0.0 involves validating SAML responses against stored AuthnRequest IDs to prevent such attacks. Defenders should prioritize verifying SAML response validation in Python Social Auth configurations.

Defensive priority

Defenders should prioritize verifying SAML response validation in Python Social Auth configurations, especially for applications using SAML account association.

Recommended defensive actions

• Verify SAML response validation in Python Social Auth configurations
• Review account association settings for SAML backends
• Update to version 5.0.0 or later if using an affected version
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, but additional verification is needed to confirm affected versions and remediation steps. The issue affects applications using the SAML backend together with authenticated account association. Defenders should verify SAML response validation in Python Social Auth configurations, especially for applications using SAML account association.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.