CVE-2026-57175: Social auth core Social-auth-core Has An Improper Authentication Vulnerability

MODERATE
Advisory Identifier: GHSA-vq6g-g6c7-5f2j
CVSS 6.4
CWE-287
Published
Advisory Summary

CVE-2026-57175 is a MODERATE (CVSS 6.4) social-auth-core has an improper authentication vulnerability (CWE-287: Improper Authentication) affecting Social auth core libraries in the PyPI ecosystem. The issue involves social-auth-core has an improper authentication issue. Remediation is available by upgrading affected packages to version 5.0.0.

CVE-2026-57175 at a Glance

CVE Identifier CVE-2026-57175
GHSA Identifier GHSA-vq6g-g6c7-5f2j
Severity MODERATE
CVSS v3.1 Base Score 6.4
CWE Classification CWE-287: Improper Authentication
Affected Product Social auth core
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 6.4

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required Low (PR:L)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2026-57175

To remediate this vulnerability, upgrade all affected Social auth core dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

social-auth-core fixed: 5.0.0
pip install social-auth-core>=5.0.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

pip show social-auth-core

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-57175, inspect your installed packages using pip:

pip show social-auth-core

Analyze the terminal output to locate any version of Social auth core in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 5.0.0), your application is affected.

Note: The pip show social-auth-core command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-287: Improper Authentication, where when an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. In Social auth core, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact The SAML backend accepted SAML responses on the Assertion Consumer Service endpoint without verifying that they matched a previously issued `AuthnRequest`. Applications using SAML account association could allow an attacker with a valid account on a trusted IdP to link the attacker's SAML identity to a logged-in victim's local account. The attacker could then authenticate through SAML and gain access to the victim's account. The issue affects applications using the SAML backend together with authenticated account association. ### Patches The issue has been fixed by validating SAML responses against stored `AuthnRequest` IDs. Users should upgrade to a patched version. Fix: * https://github.com/python-social-auth/social-core/pull/1794 ### Workarounds Applications that cannot upgrade immediately should disable SAML account association for already authenticated users. If SAML login is not required, the SAML backend can also be disabled by removing it from `SOCIAL_AUTH_AUTHENTICATION_BACKENDS`. There is no complete workaround while continuing to allow vulnerable SAML account association. ### Credits Reported through GitHub private vulnerability reporting by Liyi Zhou, Ziyue Wang, Strick, Maurice, and Chenchen Yu from the University of Sydney security research team. Reporter references: * https://lzhou1110.github.io/ * https://zyy0530.github.io/ * https://str1ckl4nd.github.io/ * https://maurice.busystar.org/ * https://7thparkk.github.io/

CVE-2026-57175 Affected Social auth core Versions

1 component(s)
Fixed Versions:
5.0.0
Product / Package Ecosystem Affected Versions Fixed Version
social-auth-core
PyPI
< 5.0.0
5.0.0

References

Frequently Asked Questions

What is CVE-2026-57175?
CVE-2026-57175 is a security vulnerability in Social auth core involving social-auth-core has an Improper Authentication issue under CWE-287: Improper Authentication.
Which Social auth core versions are affected?
Affected versions include releases prior to 5.0.0 across affected packages: social-auth-core.
What version fixes CVE-2026-57175?
Upgrading to 5.0.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is social-auth-core affected?
Yes, social-auth-core is affected in releases prior to 5.0.0. Upgrade your dependency to 5.0.0 or later.
What is the CVSS score of CVE-2026-57175?
CVE-2026-57175 has a CVSS v3.1 base score of 6.4 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2026-57175?
CVE-2026-57175 is classified under CWE-287: Improper Authentication (When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.).
How can I check PyPI dependencies for CVE-2026-57175?
Run the dependency tree command: 'pip show social-auth-core'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-vq6g-g6c7-5f2j",
  "modified" : "2026-09-24T19:54:48Z",
  "published" : "2026-09-24T19:54:48Z",
  "aliases" : [ "CVE-2026-57175" ],
  "summary" : "social-auth-core has an Improper Authentication issue",
  "details" : "### Impact\n\nThe SAML backend accepted SAML responses on the Assertion Consumer Service endpoint without verifying that they matched a previously issued `AuthnRequest`.\n\nApplications using SAML account association could allow an attacker with a valid account on a trusted IdP to link the attacker's SAML identity to a logged-in victim's local account. The attacker could then authenticate through SAML and gain access to the victim's account.\n\nThe issue affects applications using the SAML backend together with authenticated account association.\n\n### Patches\n\nThe issue has been fixed by validating SAML responses against stored `AuthnRequest` IDs.\n\nUsers should upgrade to a patched version.\n\nFix:\n\n* https://github.com/python-social-auth/social-core/pull/1794\n\n### Workarounds\n\nApplications that cannot upgrade immediately should disable SAML account association for already authenticated users.\n\nIf SAML login is not required, the SAML backend can also be disabled by removing it from `SOCIAL_AUTH_AUTHENTICATION_BACKENDS`.\n\nThere is no complete workaround while continuing to allow vulnerable SAML account association.\n\n### Credits\n\nReported through GitHub private vulnerability reporting by Liyi Zhou, Ziyue Wang, Strick, Maurice, and Chenchen Yu from the University of Sydney security research team.\n\nReporter references:\n\n* https://lzhou1110.github.io/\n* https://zyy0530.github.io/\n* https://str1ckl4nd.github.io/\n* https://maurice.busystar.org/\n* https://7thparkk.github.io/",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "social-auth-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "5.0.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/python-social-auth/social-core/security/advisories/GHSA-vq6g-g6c7-5f2j"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-57175"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/python-social-auth/social-core/pull/1794"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/python-social-auth/social-core/commit/5c72f71125bc60e4411f09e2a9f998de5da7fcb6"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/python-social-auth/social-core"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/python-social-auth/social-core/releases/tag/5.0.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-287" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-24T19:54:48Z",
    "nvd_published_at" : "2026-09-24T18:17:14Z"
  }
}