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Fencer Intel
high 7.4

CVE-2026-57178 json

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

published 4mo ago modified last mo. also EUVD-2026-86312 , GHSA-3c93-f73f-qc9h , PYSEC-2026-4165

cvss
7.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits
0
none known

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.

Patch / fix

  • pypi social-auth-core 5.0.0
  • social-auth-core Debian 14 5.0.2-1

debian advisories DEBIAN-CVE-2026-57178

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-57178 updated cvss 7.4

social-auth-core: social-auth-core: Authentication bypass via missing signature verification in VK App backend

  • Red Hat Ansible Automation Platform 2 automation-controller 4.7.17-1.el9ap, ansible-automation-platform-24/controller-rhel8
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Ansible Automation Platform 2 python-social-auth-core 4.4.2-1.el9ap, python3x-social-auth-core 4.4.2-1.el8ap, ansible-automation-platform-24/hub-rhel8, ansible-automation-platform-25/hub-rhel8, ansible-automation-platform-26/hub-rhel9, ansible-automation-platform-27/hub-rhel9, +12 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
last mo.

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
GitHub 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
OSV 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected packages

ecosystem package affected fixed in
pypi social-auth-core
<5.0.0
5.0.0

Affected products

  • python-social-auth social-core

Classification

Weakness
  • CWE-287 Improper Authentication
  • CWE-347 Improper Verification of Cryptographic Signature

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of python-social-auth/social-core published their own advisory on GitHub. Reviewed sources take precedence over it.