How severe is GHSA-3c93-f73f-qc9h?

GHSA-3c93-f73f-qc9h has a CVSS score of 7.4/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-3c93-f73f-qc9h?

GHSA-3c93-f73f-qc9h affects the following packages: social-auth-core (PyPI). Ecosystems affected: PyPI.

How do I fix GHSA-3c93-f73f-qc9h?

Update social-auth-core to 5.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-3c93-f73f-qc9h is resolved across your whole dependency graph.

How do I detect GHSA-3c93-f73f-qc9h in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for social-auth-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-3c93-f73f-qc9h if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is GHSA-3c93-f73f-qc9h actively exploited in the wild?

No public exploit code has been indexed for GHSA-3c93-f73f-qc9h yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-3c93-f73f-qc9h?

GHSA-3c93-f73f-qc9h has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 5th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-3c93-f73f-qc9h?

GHSA-3c93-f73f-qc9h is classified as Improper Authentication (CWE-287), CWE-347 (CWE-347). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-3c93-f73f-qc9h published, and has it been updated?

GHSA-3c93-f73f-qc9h was published on September 24, 2026 and was last updated on October 1, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

HIGH severity

social-auth-core: VK App backend accepts unsigned callback data when auth_key is missingGHSA-3c93-f73f-qc9h

HIGHFix: python-social-auth/social-core#1811

GHSA-3c93-f73f-qc9h is a high-severity (CVSS 7.4) Improper Authentication vulnerability in social-auth-core. A fix is available for social-auth-core — see the affected versions and patch details below.

Also known asCVE-2026-57178PYSEC-2026-4165

Published

Sep 24, 2026

Updated

Oct 1, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 24, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-3c93-f73f-qc9h.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs5th percentile — riskier than 5% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

GHSA-3c93-f73f-qc9h by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 394,803 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

🐍social-auth-core

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Impact

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.

Patches

The issue has been fixed by requiring auth_key to be present and valid before callback data is trusted.

Users should upgrade to a patched version.

Fix:

https://github.com/python-social-auth/social-core/pull/1811

Workarounds

Applications that cannot upgrade immediately should disable the vk-app backend by removing social_core.backends.vk.VKAppOAuth2 from SOCIAL_AUTH_AUTHENTICATION_BACKENDS.

There is no complete workaround while continuing to use the vulnerable backend.

Credits

Reported by @lalalala5678 through GitHub private vulnerability reporting.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`social-auth-core`	all versions	5.0.0`pip install --upgrade 'social-auth-core==5.0.0'`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for social-auth-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update social-auth-core to 5.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-3c93-f73f-qc9h is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

This vulnerability is rated as having an Important severity because an unauthenticated remote attacker could forge identity attributes and impersonate arbitrary users, compromising access controls without requiring privileged credentials. Exploitation is strictly contingent on the application explicitly enabling the…

Workaround published by Red Hat

To mitigate this vulnerability, ensure that the VK App authentication backend is disabled. If configured, remove `social_core.backends.vk.VKAppOAuth2` from the `SOCIAL_AUTH_AUTHENTICATION_BACKENDS` setting in your application configuration. Note that disabling this backend prevents users from authenticating through the VK App provider. A restart of the application services is required for configuration changes to take effect.

Source: Red Hat security advisory for GHSA-3c93-f73f-qc9h (CC BY 4.0)

Frequently Asked Questions

### Impact 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. ### Patches The issue has been fixed by requiring `auth_key` to be present and valid before callback d