XSS in Zulip
CVE-2025-52559
Zulip is an open-source team chat application. From versions 2.0.0-rc1 to before 10.4 in Zulip Server, the /digest/ URL of a server shows a preview of what the email weekly digest would contain. This URL, though not the digest itself, contains a cross-site scripting (XSS) vulnerability in both topic names and channel names. This issue has been fixed in Zulip Server 10.4. A workaround for this issue involves denying access to /digest/.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.003 (19.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 19.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
- Zulip — versions >= 2.0.0-rc1, < 10.4
- Zulip Server — versions 2.0.0
Weakness classification (CWE)
References
- github.com/zulip/zulip/security/advisories/GHSA-vgf2-vw4r-m663 (Patch, Vendor Advisory)
- github.com/zulip/zulip/commit/175ec1f365b0db982d6eac9019701cbf6e8bc2f2 (Patch)
- github.com/zulip/zulip/commit/1a8429e338ff53bdcc4b42e7e71b6fffdd84fcd1 (Patch)
- github.com/zulip/zulip/commit/6608c8777254e73a4b540e5e1c4af92e680a55fc (Patch)
Frequently asked questions
- What is CVE-2025-52559?
- CVE-2025-52559 is a medium-severity vulnerability in Zulip, classified under Cross-site Scripting. CVSS score: 6.8/10. Published 2025-07-02.
- How severe is CVE-2025-52559?
- Medium severity. CVSS v3 base score is 6.8 out of 10.