CVE-2025-47930: Zulip Server has access control bypass for restrictions on creation of specific channel types
Description
Zulip is an open-source team chat application. Starting in version 10.0 and prior to version 10.3, the "Who can create public channels" access control mechanism can be circumvented by creating a private or web-public channel, and then changing the channel privacy to public. A similar technique works for creating private channels without permission, though such a process requires either the API or modifying the HTML, as we do mark the "private" radio button as disabled in such cases. Version 10.3 contains a patch.
Classification
CVE ID: CVE-2025-47930
CVSS Base Severity: MEDIUM
CVSS Base Score: 5.3
CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Problem Types
CWE-863: Incorrect AuthorizationAffected Products
Vendor: zulip
Product: zulip
Exploit Prediction Scoring System (EPSS)
EPSS Score: 0.04% (probability of being exploited)
EPSS Percentile: 12.86% (scored less or equal to compared to others)
EPSS Date: 2025-06-13 (when was this score calculated)
References
https://nvd.nist.gov/vuln/detail/CVE-2025-47930https://github.com/zulip/zulip/security/advisories/GHSA-rqg7-xfqg-v7q5
https://github.com/zulip/zulip/commit/d2ff4bda4c3efa30fc3ab1f151255cfdbf370f78
https://zulip.com/help/configure-who-can-create-channels
https://zulip.readthedocs.io/en/latest/overview/changelog.html#zulip-server-10-3