CVE-2026-102893
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.
- CVSS 4.0
- 9.1
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 - EPSS
- 0.4% chance of exploitation in the next 30 days; higher than 32% of CVEs (scores of 2026-10-25)
- CWE
- CWE-287
- Published
- Modified
- Record from
- the NVD, synced
References
- https://github.com/zulip/zulip/commit/68d2d9defa39f8af96a50fc7430efc34dee120b5
- https://github.com/zulip/zulip/commit/b40f191a8c71e74fcb471f71de6a1233de157102
- https://github.com/zulip/zulip/pull/39913
- https://github.com/zulip/zulip/releases/tag/12.2
- https://github.com/zulip/zulip/security/advisories/GHSA-xw9h-9rcm-hx4m