# CVE-2026-57179: social-auth-core has a Session Fixation issue

> Attackers can hijack victim sessions by exploiting unbound partial tokens in resumable authentication flows, leading to unauthorized account access.

- **Severity:** Medium 4.2 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 24 Sep 2026
- **Updated:** 24 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-57179, GHSA-vqg6-3fw6-j9jg, PYSEC-2026-4168, UBUNTU-CVE-2026-57179

## What is CVE-2026-57179?

CVE-2026-57179 is a medium-severity authentication bypass vulnerability in python-social-auth social-core, published on 24 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Python Social Auth is a social authentication/registration mechanism. Prior to version 5.0.0, the partial-pipeline resume mechanism accepted `partial_token` as a bearer credential without binding it to the browser session that created it. Applications using resumable partial pipeline steps could allow an attacker to start an authentication flow, obtain a valid partial token and verification data, and cause a victim's browser to resume that attacker-controlled flow. This could authenticate the victim's browser as the attacker's account. The issue affects applications using partial pipeline steps such as `mail_validation` or custom steps decorated with `@partial`. The issue has been fixed in version 5.0.0 by binding partial pipeline resumes to the originating browser session.

Weakness: CWE-384 (Session Fixation)

## Which versions are affected by CVE-2026-57179?

3 open source packages ship an affected version, including social-auth-core.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `social-auth-core` | PyPI | All versions | 5.0.0 |
| `social-auth-core` | PyPI | All versions | 5.0.0 |
| `social-auth-core` | PyPI | All versions | 5.0.0 |

## How do I fix CVE-2026-57179?

Upgrade social-auth-core to 5.0.0 or later.

## Is CVE-2026-57179 being exploited?

There is no known exploitation of CVE-2026-57179 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-57179 and fix it if it is affected.

What it is: CVE-2026-57179 is a medium-severity authentication bypass vulnerability in python-social-auth social-core, published on 24 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-57179 in the wild and no public exploit code.

Affected packages and fixed versions:
- social-auth-core (PyPI): affected all versions; fixed in 5.0.0
- social-auth-core (PyPI): affected all versions; fixed in 5.0.0
- social-auth-core (PyPI): affected all versions; fixed in 5.0.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-57179/ (Markdown: https://insights.sbomify.com/CVE-2026-57179/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-57179
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-57179
- OSV: https://osv.dev/vulnerability/CVE-2026-57179

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-57179/
Summaries are generated and may contain mistakes; the official description above is the record.