Zulip XSS in digest preview URL

published 2025-07-02 16 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-19763

cvss: 6.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 21%
public exploits: 0; none known

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/.

Patch / fix

fixed in 2 links 4

zulip zulip 10.4
zulip zulip_server 10.4

github.com/zulip/zulip@175ec1f commit
github.com/zulip/zulip@1a8429e commit
github.com/zulip/zulip@6608c87 commit
github.com/zulip/zulip/security/advisories/GHSA-vgf2-vw4r-m663 advisory

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 16 mo ago (2025-07-02)

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.8	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N
NVD	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Affected products

zulip zulip

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

CVE List CVE-2025-52559
NVD CVE-2025-52559

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary