Vulnerability-Lookup

GHSA-3C93-F73F-QC9H

Vulnerability from github – Published: 2026-09-24 19:57 – Updated: 2026-09-24 19:57

Summary

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

Details

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.

Severity

7.4 (High)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Show details on source website

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "social-auth-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.0.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-57178"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-287",
      "CWE-347"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-24T19:57:22Z",
    "nvd_published_at": "2026-09-24T18:17:14Z",
    "severity": "HIGH"
  },
  "details": "### Impact\n\nThe `vk-app` backend accepted VK application callback data without verifying the callback signature when the `auth_key` parameter was omitted.\n\nApplications 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.\n\nThe issue affects only applications using the `vk-app` backend.\n\n### Patches\n\nThe issue has been fixed by requiring `auth_key` to be present and valid before callback data is trusted.\n\nUsers should upgrade to a patched version.\n\nFix:\n\n* https://github.com/python-social-auth/social-core/pull/1811\n\n### Workarounds\n\nApplications that cannot upgrade immediately should disable the `vk-app` backend by removing `social_core.backends.vk.VKAppOAuth2` from `SOCIAL_AUTH_AUTHENTICATION_BACKENDS`.\n\nThere is no complete workaround while continuing to use the vulnerable backend.\n\n### Credits\n\nReported by @lalalala5678 through GitHub private vulnerability reporting.",
  "id": "GHSA-3c93-f73f-qc9h",
  "modified": "2026-09-24T19:57:22Z",
  "published": "2026-09-24T19:57:22Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/python-social-auth/social-core/security/advisories/GHSA-3c93-f73f-qc9h"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-57178"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python-social-auth/social-core/pull/1811"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python-social-auth/social-core/commit/1bfacdd0379e5eb46e169a99ab648b835e9bb6a2"
    },
    {
      "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"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "social-auth-core: VK App backend accepts unsigned callback data when auth_key is missing"
}

CVE-2026-57178 (GCVE-0-2026-57178)

Vulnerability from cvelistv5 – Published: 2026-09-24 17:25 – Updated: 2026-09-24 17:25

Title

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

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.

Severity

7.4 (High)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

CWE

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

Assigner

GitHub_M mitre root

References

1 reference

URL	Tags
https://github.com/python-social-auth/social-core…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version
python-social-auth	social-core	Affected: < 5.0.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "social-core",
          "vendor": "python-social-auth",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 5.0.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.4,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-287",
              "description": "CWE-287: Improper Authentication",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-347",
              "description": "CWE-347: Improper Verification of Cryptographic Signature",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-24T17:25:47.225Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/python-social-auth/social-core/security/advisories/GHSA-3c93-f73f-qc9h",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/python-social-auth/social-core/security/advisories/GHSA-3c93-f73f-qc9h"
        }
      ],
      "source": {
        "advisory": "GHSA-3c93-f73f-qc9h",
        "discovery": "UNKNOWN"
      },
      "title": "social-auth-core: VK App backend accepts unsigned callback data when auth_key is missing"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-57178",
    "datePublished": "2026-09-24T17:25:47.225Z",
    "dateReserved": "2026-06-24T01:47:55.286Z",
    "dateUpdated": "2026-09-24T17:25:47.225Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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