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CVE-2026-57178PYSEC-2026-4165GHSA-3C93-F73F-QC9H

social-auth-core: VK App backend accepts unsigned callback data when auth_key is missing

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.0.0
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: total

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.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: no · Technical impact: total

  3. Record last updated

Affected versions

  • python-social-auth social-core

    fixed in 5.0.0

  • social-auth-corePyPI

    fixed in 5.0.0

References 1

GitHub · python-social-auth/social-core