CVE-2026-100404
CVE-2026-100404 · Zulip: Guests can read new messages in non-subscribed public channels
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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 6.5 · Medium · EPSS 0.4%
- Published
- Updated
Affected products and versions
zulip
- Versions
- < 12.2: Affected
No fix published
Original sources
- https://github.com/zulip/zulip/security/advisories/GHSA-5r8f-gq2h-fcgp
- https://github.com/zulip/zulip/pull/39913
- https://github.com/zulip/zulip/commit/98659a41cb93d4ce329ea14bb0cdfb4b147500ba
- https://github.com/zulip/zulip/commit/c03db8916456674df3c98614f6f0ef8cd024ef11
- https://github.com/zulip/zulip/releases/tag/12.2
- https://nvd.nist.gov/vuln/detail/CVE-2026-100404