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xwiki-contrib/macro-plantuml · Security

XWiki PlantUML Macro Vulnerable to Server-Side Request Forgery (SSRF) via 'server' parameter

GHSA ID
GHSA-42fc-7w97-8vrc
CVE ID
CVE-2026-42140
Severity
medium
Published
Updated
CVSS
4.4 · CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N
CVSS v3
4.4 · CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N

Description

Impact

The PlantUML Macro is vulnerable to Server-Side Request Forgery (SSRF). The macro allows users to specify an alternative PlantUML server via the server parameter. However, the application does not validate the supplied URL. An attacker can supply an internal IP address or a malicious external URL. The XWiki server will attempt to connect to this URL to "render" the diagram.

This issue affects all versions of the Plant UML Macro extension till version 2.4 included.

Patches

Version 2.4.1 of the Plant UML Macro extension fixes the issue by verifying if the supplied server domain matches one of the trusted domain configured inside of XWiki.

Workarounds

Protect the XWiki server by placing it in a DMZ so that it cannot access any other internal servers.

Resources

The issue was fixed in PLANTUML-25 by the commit c8b19bda93058794e04c8862fc7ca85c59b5fe5c.

For more information

If there are any questions or comments about this advisory:

Attribution

The issue was reported by Łukasz Rybak.

CWEs

  • CWE-918 · Server-Side Request Forgery (SSRF)

References

Open GitHub