{"id":"CVE-2026-57178","state":"PUBLISHED","title":"social-auth-core: VK App backend accepts unsigned callback data when auth_key is missing","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.","publishedAt":"2026-09-24T17:25:47.225Z","updatedAt":"2026-09-28T17:34:38.454Z","severity":{"score":7.4,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["python-social-auth social-core"],"affected":[{"vendor":"python-social-auth","product":"social-core","versions":[{"version":"< 5.0.0","status":"affected"}]}],"references":["https://github.com/python-social-auth/social-core/security/advisories/GHSA-3c93-f73f-qc9h"],"weaknesses":["CWE-287","CWE-347"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/57xxx/CVE-2026-57178.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-57178","state":"PUBLISHED","datePublished":"2026-09-24T17:25:47.225Z","dateUpdated":"2026-09-28T17:34:38.454Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-24T01:47:55.286Z"},"containers":{"cna":{"title":"social-auth-core: VK App backend accepts unsigned callback data when auth_key is missing","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."}],"affected":[{"vendor":"python-social-auth","product":"social-core","versions":[{"version":"< 5.0.0","status":"affected"}]}],"references":[{"url":"https://github.com/python-social-auth/social-core/security/advisories/GHSA-3c93-f73f-qc9h","name":"https://github.com/python-social-auth/social-core/security/advisories/GHSA-3c93-f73f-qc9h","tags":["x_refsource_CONFIRM"]}],"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","lang":"en","description":"CWE-287: Improper Authentication","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-347","lang":"en","description":"CWE-347: Improper Verification of Cryptographic Signature","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-24T17:25:47.225Z"},"source":{"advisory":"GHSA-3c93-f73f-qc9h","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-28T17:34:29.013431Z","id":"CVE-2026-57178","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-28T17:34:38.454Z"}}]}}}