{"id":"CVE-2026-93631","summary":"Zimbra Collaboration Suite OAuth Extension Cross-Site Request Forgery Enables Account Linking","details":"A cross-site request forgery vulnerability in the OAuth extension of Zimbra Collaboration Suite (ZCS) Network Edition allows an attacker to link an attacker-controlled external account to a victim's mailbox. The OAuth callback does not bind its state value or authorization code to the initiating Zimbra session and instead selects the destination mailbox from the browser's current authentication cookie. On a deployment with the provider configured, an attacker can induce a signed-in victim to load a callback containing a fresh code for the attacker's provider account. This creates a persistent data source that imports attacker-controlled contacts or events. With bidirectional CalDAV synchronization, appointments subsequently created or edited in the linked calendar are also disclosed to the attacker. ZCS 10.1.16 and 10.1.20 are affected.","modified":"2026-11-08T02:47:43.357060742Z","published":"2026-10-23T13:23:34.952Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93631.json","unresolved_ranges":[{"extracted_events":[{"range":[{"last_affected":"10.1.20"}],"source":"AFFECTED_FIELD","strategy":"StandardRange"}]}],"cna_assigner":"rapid7","cwe_ids":["CWE-352"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93631.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93631"},{"type":"ADVISORY","url":"https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories"},{"type":"ARTICLE","url":"https://www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1/"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/zimbra/zm-build","events":[{"introduced":"0"},{"last_affected":"c4837c66360979d757890271f6c976727e71bcad"}],"database_specific":{"extracted_events":[{"source":"CPE_RANGE","cpe":"cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:*","range":[{"introduced":"0"},{"last_affected":"10.1.20"}]}]}}],"versions":["10.1.20","10.1.16","10.1.14","10.1.13","10.1.10","10.1.6","10.1.5","10.1.4","10.1.1","10.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93631.json"}},{"ranges":[{"type":"GIT","repo":"https://github.com/zimbra/zm-mailbox","events":[{"introduced":"0"},{"last_affected":"c80d2bbf562968d44fa90edd843f1985026585c3"}],"database_specific":{"extracted_events":[{"range":[{"introduced":"0"},{"last_affected":"10.1.20"}],"source":"CPE_RANGE","cpe":"cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:*"}]}}],"versions":["10.1.20","10.1.18","10.1.17","10.1.16","10.1.14","10.1.13","10.1.10","10.1.8","10.1.7","10.1.6","10.1.5","10.1.4","10.1.3","10.1.2","10.1.1","10.1.0","8.8.11"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93631.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N"}]}