social-auth-core: VK App backend accepts unsigned callback data when auth_key is missing
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-287.
Summary
Python Social Auth is a social authentication/registration mechanism. Prior to version 5.0.0, the `vk-app` backend accepted VK application callback data without verifying the callback signature when the `auth_key` parameter was omitted. Applications using this backend could treat unsigned attacker-controlled data as a verified VK identity. An attacker could choose callback fields such as `viewer_id`, `access_token`, `api_id`, and `api_result`, potentially allowing authentication as an arbitrary VK user ID. The issue affects only applications using the `vk-app` backend. The issue has been fixed in version 5.0.0 by requiring `auth_key` to be present and valid before callback data is trusted.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| python-social-auth | social-core | before 5.0.0 | 5.0.0 | Patch available | CNA |
| — | social-auth-core (PyPI) | before 5.0.0 | 5.0.0 | Patch available | GHSA-3c93-f73f-qc9h |
- social-core Vendorpython-social-auth Affected before 5.0.0 Fixed in 5.0.0 Patch available CNA
- social-auth-core (PyPI) Vendor— Affected before 5.0.0 Fixed in 5.0.0 Patch available GHSA-3c93-f73f-qc9h
Remediation
- Fix · CNA social-core (python-social-auth) Fixed in 5.0.0
- Fix · GHSA-3c93-f73f-qc9h social-auth-core (PyPI) Fixed in 5.0.0 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Ansible Automation Platform 2 | Affected | No fix planned: Will not fix |
Not affected: 1 product
- Red Hat Ansible Automation Platform 2
Timeline
- 2026-10-02 Threatist record created from CVE-2026-57178
- 2026-10-03 Alias added: GHSA-3c93-f73f-qc9h
- 2026-10-21 Affected versions changed · Red Hat
References
Other 5
- https://github.com/python-social-auth/social-core/security/advisories/GHSA-3c93-f73f-qc9h
- https://github.com/python-social-auth/social-core/pull/1811
- https://github.com/python-social-auth/social-core/commit/1bfacdd0379e5eb46e169a99ab648b835e9bb6a2
- https://github.com/python-social-auth/social-core
- https://github.com/python-social-auth/social-core/releases/tag/5.0.0
More python-social-auth vulnerabilities
- TI-2026-80499 OpenID Connect nonce not bound to session in Python Social Auth CVSS 3.1MEDIUM 6.8
- TI-2025-38176 Python Social Auth - Django has unsafe account association CVSS 4.0MEDIUM 6.3
- TI-2026-41142 social-auth-core Vulnerable to Account Takeover via Identity Binding Flaw in Vend Backend CVSS 3.1MEDIUM 6.8
- TI-2026-41141 social-auth-core has an Improper Authentication issue CVSS 3.1MEDIUM 6.4
- TI-2026-74654 Login CSRF in Python Social Auth LINE backend CVSS 3.1MEDIUM 6.5
- TI-2024-21751 social-auth-app-django Improper Handling of Case Sensitivity vulnerability CVSS 3.1MEDIUM 4.9
Sources
- CVE-2026-57178 · CVE Program
- CVE-2026-57178 · NVD
- FIRST EPSS
- GHSA-3c93-f73f-qc9h · GitHub Advisory Database · CC BY 4.0
- CVE-2026-57178 · Red Hat security data · CC BY 4.0
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