{"id":"CVE-2026-102893","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-102893","generatedAt":"2026-10-28T04:37:30.620Z","title":"Zulip is an open-source team collaboration tool.","description":"Zulip is an open-source team collaboration tool. In Zulip Server versions through 12.1, GenericOpenIdConnectBackend matches the identity provider email claim to an active account's delivery_email without rejecting an explicitly false email_verified claim. If a configured identity provider returns an email address that the authenticating user does not control together with email_verified=false, Zulip can log the user into the existing account for that address. Exploitation requires a misconfigured trusted identity provider, and deployments whose authoritative identity provider only emits email addresses controlled by the authenticating user are not affected. This issue is fixed in version 12.2.","published":"2026-10-14T16:17:30.000Z","lastModified":"2026-10-16T20:02:38.000Z","status":"Awaiting Analysis","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"4.0","score":9.1,"severity":"CRITICAL","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-287"],"affected":[],"epss":{"score":0.0039,"percentile":0.32895,"date":"2026-10-27","history":[{"date":"2026-10-15","score":0.0039,"percentile":0.31415}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.39%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-14T16:17:30.000Z","detail":{"score":"9.1","severity":"CRITICAL","publishedAt":"2026-10-14T16:17:29.987Z"},"summary":"New CVE, critical severity (CVSS 9.1)."}],"references":[{"url":"https://github.com/zulip/zulip/commit/68d2d9defa39f8af96a50fc7430efc34dee120b5","source":"security-advisories@github.com"},{"url":"https://github.com/zulip/zulip/commit/b40f191a8c71e74fcb471f71de6a1233de157102","source":"security-advisories@github.com"},{"url":"https://github.com/zulip/zulip/pull/39913","source":"security-advisories@github.com"},{"url":"https://github.com/zulip/zulip/releases/tag/12.2","source":"security-advisories@github.com"},{"url":"https://github.com/zulip/zulip/security/advisories/GHSA-xw9h-9rcm-hx4m","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-102893","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}