CVE intelligence and bounded remediation

CVE-2025-52559 — Zulip is an open-source team chat application

Medium CVSS 6.8

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/.

Severity
Medium
CVSS
6.8 (3.1)
Published
2025-07-02
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-79

Affected products

  • zulip / zulip_server
  • zulip / zulip_server / 2.0.0

Matched remediation archetype

Cross-site scripting and unsafe browser output

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
  • Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
  • Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.

Remediate safely

  • Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
  • Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
  • Update affected rendering components and add tests for every output context using inert sentinel markup.

Authoritative sources

Complete CVE record and remediation plan

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