{"id":"CVE-2026-57178","published":"2026-09-24T18:17:14.970","lastModified":"2026-09-28T18:17:23.873","description":"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.","cvssScore":7.4,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","cwes":["CWE-287","CWE-347"],"vendors":[],"products":[],"references":[{"url":"https://github.com/python-social-auth/social-core/security/advisories/GHSA-3c93-f73f-qc9h","tags":[]}],"exploitRefs":[{"url":"https://github.com/python-social-auth/social-core/security/advisories/GHSA-3c93-f73f-qc9h","tags":[]}],"hasPoc":true,"ai":null}