{"id":"CVE-2026-102893","state":"PUBLISHED","title":"Zulip: OpenID Connect authentication ignores the email_verified claim","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.","publishedAt":"2026-10-14T15:49:03.442Z","updatedAt":"2026-10-15T19:06:20.918Z","severity":{"score":9.1,"label":"Critical","version":"4.0","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","source":"GitHub_M"},"assigner":"GitHub_M","products":["zulip zulip"],"affected":[{"vendor":"zulip","product":"zulip","versions":[{"version":"< 12.2","status":"affected"}]}],"references":["https://github.com/zulip/zulip/security/advisories/GHSA-xw9h-9rcm-hx4m","https://github.com/zulip/zulip/pull/39913","https://github.com/zulip/zulip/commit/68d2d9defa39f8af96a50fc7430efc34dee120b5","https://github.com/zulip/zulip/commit/b40f191a8c71e74fcb471f71de6a1233de157102","https://github.com/zulip/zulip/releases/tag/12.2"],"weaknesses":["CWE-287"],"ingestedAt":"2026-10-29T20:10:13.529Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/102xxx/CVE-2026-102893.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-102893","state":"PUBLISHED","datePublished":"2026-10-14T15:49:03.442Z","dateUpdated":"2026-10-15T19:06:20.918Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-09-29T17:34:42.743Z"},"containers":{"cna":{"title":"Zulip: OpenID Connect authentication ignores the email_verified claim","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"zulip","product":"zulip","versions":[{"version":"< 12.2","status":"affected"}]}],"references":[{"url":"https://github.com/zulip/zulip/security/advisories/GHSA-xw9h-9rcm-hx4m","name":"https://github.com/zulip/zulip/security/advisories/GHSA-xw9h-9rcm-hx4m","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/zulip/zulip/pull/39913","name":"https://github.com/zulip/zulip/pull/39913","tags":["x_refsource_MISC"]},{"url":"https://github.com/zulip/zulip/commit/68d2d9defa39f8af96a50fc7430efc34dee120b5","name":"https://github.com/zulip/zulip/commit/68d2d9defa39f8af96a50fc7430efc34dee120b5","tags":["x_refsource_MISC"]},{"url":"https://github.com/zulip/zulip/commit/b40f191a8c71e74fcb471f71de6a1233de157102","name":"https://github.com/zulip/zulip/commit/b40f191a8c71e74fcb471f71de6a1233de157102","tags":["x_refsource_MISC"]},{"url":"https://github.com/zulip/zulip/releases/tag/12.2","name":"https://github.com/zulip/zulip/releases/tag/12.2","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":9.1,"baseSeverity":"CRITICAL","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-287","lang":"en","description":"CWE-287: Improper Authentication","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-14T15:49:03.442Z"},"source":{"advisory":"GHSA-xw9h-9rcm-hx4m","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-15T19:05:46.384884Z","id":"CVE-2026-102893","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-15T19:06:20.918Z"}}]}}}