Cross-site scripting in Zulip Server - CVE-2025-52559
Published: July 16, 2025
Vulnerability identifier: #VU112981
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2025-52559
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data in digest preview URL. A remote user can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
Affected software
Zulip Server
How to mitigate CVE-2025-52559
Install update from vendor's website.
Zulip Server - update to 10.4
External References
- https://github.com/zulip/zulip/commit/175ec1f365b0db982d6eac9019701cbf6e8bc2f2
- https://github.com/zulip/zulip/commit/1a8429e338ff53bdcc4b42e7e71b6fffdd84fcd1
- https://github.com/zulip/zulip/commit/6608c8777254e73a4b540e5e1c4af92e680a55fc
- https://github.com/zulip/zulip/security/advisories/GHSA-vgf2-vw4r-m663