{"id":"CVE-2026-52841","summary":"Easy!Appointments: Authorization bypass in Google OAuth provider binding lets any backend user rebind a peer provider's Google sync","details":"Easy!Appointments is a self hosted appointment scheduler. In versions prior to 1.6.0, `Google::oauth` at `application/controllers/Google.php:278` stores its URL-supplied `provider_id` in the session, and `oauth_callback` saves the issued Google OAuth token against that row without checking the caller owns the provider. Any logged-in backend user (admin, provider, or secretary) rebinds a peer provider's Google sync to a Google account they control. The peer's appointments then sync into the attacker's calendar with each customer's name and email attached as attendee data. Version 1.6.0 patches the issue.","aliases":["GHSA-8hm4-r66f-29wr"],"modified":"2026-07-16T03:48:36.869221065Z","published":"2026-07-14T15:27:50.367Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-639"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52841.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52841.json"},{"type":"ADVISORY","url":"https://github.com/alextselegidis/easyappointments/security/advisories/GHSA-8hm4-r66f-29wr"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-52841"},{"type":"FIX","url":"https://github.com/alextselegidis/easyappointments/commit/4b2d245d2cd2058dc76e05f6eb65b26699268471"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/alextselegidis/easyappointments","events":[{"introduced":"0"},{"fixed":"4b2d245d2cd2058dc76e05f6eb65b26699268471"}],"database_specific":{"source":["AFFECTED_FIELD","REFERENCES"],"extracted_events":[{"introduced":"0"},{"fixed":"1.6.0"}]}}],"versions":["1.6.0-beta.2","1.6.0-beta.1","1.6.0-alpha.1","1.5.2-beta.1","1.5.1","1.5.1-beta.1","1.5.0","1.5.0-beta.1","1.5.0-alpha.1","1.5.0-dev.4","1.5.0-dev.3","1.5.0-dev.2","1.5.0-dev.1","1.3.0-beta.2","1.3.0-beta.1","1.3.0-alpha.1","1.2.0-beta.1","1.2.0-alpha.1","1.1.0","1.1.0-beta.2"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-52841.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:N"}]}