---
title: "CVE-2026-102893: Zulip Server - Authentication Bypass"
description: "Zulip Server <= 12.1 contains an authentication bypass caused by GenericOpenIdConnectBackend not rejecting false email_verified claims, letting attackers log into accounts with unverified emails, exploit requires misconfigured trusted identity provider."
url: https://panop.io/threat-heartbeat/CVE-2026-102893/
---

# CVE-2026-102893 Zulip Server - Authentication Bypass

Zulip Server <= 12.1 contains an authentication bypass caused by GenericOpenIdConnectBackend not rejecting false email\_verified claims, letting attackers log into accounts with unverified emails, exploit requires misconfigured trusted identity provider.

CVSS base score 9.1 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-102893)

## Details

Type

Authentication Bypass

Impact

Broken Authentication

CVSS 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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Published

14 October 2026

Updated

15 October 2026

Weakness

[CWE-287](https://cwe.mitre.org/data/definitions/287.html)

## Vendor fix

Upgrade to version 12.2 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-102893](https://nvd.nist.gov/vuln/detail/CVE-2026-102893)
- [https://github.com/zulip/zulip/commit/68d2d9defa39f8af96a50fc7430efc34dee120b5](https://github.com/zulip/zulip/commit/68d2d9defa39f8af96a50fc7430efc34dee120b5)
- [https://github.com/zulip/zulip/commit/b40f191a8c71e74fcb471f71de6a1233de157102](https://github.com/zulip/zulip/commit/b40f191a8c71e74fcb471f71de6a1233de157102)
- [https://github.com/zulip/zulip/pull/39913](https://github.com/zulip/zulip/pull/39913)
- [https://github.com/zulip/zulip/releases/tag/12.2](https://github.com/zulip/zulip/releases/tag/12.2)
- [https://github.com/zulip/zulip/security/advisories/GHSA-xw9h-9rcm-hx4m](https://github.com/zulip/zulip/security/advisories/GHSA-xw9h-9rcm-hx4m)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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