XWiki PlantUML Macro Vulnerable to Server-Side Request Forgery (SSRF) via 'server' parameter
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:
- Open an issue in JIRA XWiki.org
- Send an email to Security Mailing List
Attribution
The issue was reported by Łukasz Rybak.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Java / Kotlin (Maven) | org.xwiki.contrib.plantuml:macro-plantuml-macro | < 2.4.1 | 2.4.1 |
References
- https://github.com/xwiki-contrib/macro-plantuml/security/advisories/GHSA-42fc-7w97-8vrc
- https://nvd.nist.gov/vuln/detail/CVE-2026-42140
- https://github.com/xwiki-contrib/macro-plantuml/commit/c8b19bda93058794e04c8862fc7ca85c59b5fe5c
- https://github.com/xwiki-contrib/macro-plantuml
- https://jira.xwiki.org/browse/PLANTUML-25
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N- Weakness (CWE)
CWE-918- Platform
- Java / Kotlin (Maven)
- Package
org.xwiki.contrib.plantuml:macro-plantuml-macro- Disclosed
- 05.05.2026
- Updated
- 11.10.2026 12:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-42fc-7w97-8vrc - CC BY 4.0
Vulnerability history: org.xwiki.contrib.plantuml:macro-plantuml-macro
All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.
This is the only known vulnerability of this package.
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