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

Vulnerability from cvelistv5 – Published: 2026-09-24 17:25 – Updated: 2026-09-24 17:25
VLAI
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
References
Impacted products
Vendor Product Version CPE status
python-social-auth social-core Affected: < 5.0.0
guessed Create a notification for this product.
Show details on NVD website
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      "title": "social-auth-core: VK App backend accepts unsigned callback data when auth_key is missing"
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    "dateReserved": "2026-06-24T01:47:55.286Z",
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    "state": "PUBLISHED"
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          }
        ],
        "id": "CVE-2026-57178",
        "lastModified": "2026-09-25T13:27:31.790",
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      "current_release_date": "2026-09-25T08:28:23+00:00",
      "cve": "CVE-2026-57178",
      "id": "CVE-2026-57178",
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      "product_status:known_affected": "15",
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      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "social-auth-core: social-auth-core: Authentication bypass via missing signature verification in VK App backend",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-57178.json",
      "version": "3"
    }
  }
}



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