{"cve":"CVE-2026-57178","nvd":{"published":"2026-09-24T18:17:14.970","modified":"2026-09-28T18:17:23.873","status":"Awaiting Analysis","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","score":7.4},"cwes":["CWE-287","CWE-347"],"references":["https://github.com/python-social-auth/social-core/security/advisories/GHSA-3c93-f73f-qc9h"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:56:02.509636177+00:00"},"epss":{"cve":"CVE-2026-57178","score":0.0016,"percentile":0.05187,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-3c93-f73f-qc9h","url":"https://osv.dev/vulnerability/GHSA-3c93-f73f-qc9h","summary":"social-auth-core: VK App backend accepts unsigned callback data when auth_key is missing","modified":"2026-10-01T17:55:50.908917537Z","packages":[{"ecosystem":"PyPI","name":"social-auth-core","purl":"pkg:pypi/social-auth-core","ranges":["<5.0.0"],"fixed":["5.0.0"]}]},{"id":"PYSEC-2026-4165","url":"https://osv.dev/vulnerability/PYSEC-2026-4165","summary":"social-auth-core: VK App backend accepts unsigned callback data when auth_key is missing","modified":"2026-10-01T17:45:17.846162070Z","packages":[{"ecosystem":"PyPI","name":"social-auth-core","purl":"pkg:pypi/social-auth-core","ranges":["<5.0.0"],"fixed":["5.0.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}