CVE-2026-100404
mediumZulip is an open-source team collaboration tool.
Zulip is an open-source team collaboration tool. In Zulip Server versions through 12.1, guest users can receive new message events for public channels outside their subscriptions. A guest can trigger the issue by registering an event queue with parameters that request messages from an unsubscribed public channel, or an existing event queue can remain affected after the guest's access to the channel is removed. The flaw discloses new public-channel messages to the guest. This issue is fixed in version 12.2.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/zulip/zulip/commit/98659a41cb93d4ce329ea14bb0cdfb4b147500ba security-advisories@github.com
- https://github.com/zulip/zulip/commit/c03db8916456674df3c98614f6f0ef8cd024ef11 security-advisories@github.com
- https://github.com/zulip/zulip/pull/39913 security-advisories@github.com
- https://github.com/zulip/zulip/releases/tag/12.2 security-advisories@github.com
- https://github.com/zulip/zulip/security/advisories/GHSA-5r8f-gq2h-fcgp security-advisories@github.com