XWiki Rendering is vulnerable to XSS attacks through insecure XHTML syntax
Impact
The XHTML syntax depended on the xdom+xml/current syntax which allows the creation of raw blocks that permit the insertion of arbitrary HTML content including JavaScript. This allows XSS attacks for users who can edit a document like their user profile (enabled by default). The attack works by setting the document's syntax to xdom+xml/current and then inserting content like
<document><p><metadata><metadata><entry><string>syntax</string><org.xwiki.rendering.syntax.Syntax><type><name>XHTML</name><id>xhtml</id><variants class="empty-list"></variants></type><version>5</version></org.xwiki.rendering.syntax.Syntax></entry></metadata></metadata></p><rawtext syntax="html/5.0" content="<script>alert(1);</script>"></rawtext></document>This has been fixed by removing the dependency on the xdom+xml/current syntax from the XHTML syntax. Note that the xdom+xml syntax is still vulnerable to this attack. As it's main purpose is testing and its use is quite difficult, this syntax shouldn't be installed or used on a regular wiki. We're currently not aware of any further dependencies on it.
Patches
The fix of removing the dependency has been included in XWiki 14.10. It is not released for earlier versions due to the potential breakages, among others this change makes it necessary to update the Confluence XHTML syntax as it relies on internals that were changed for the fix. Similar XSS fixes were also not applied to the LTS version 13.10.x due to the potential breakages.
Workarounds
There are no known workarounds apart from upgrading.
References
- https://jira.xwiki.org/browse/XRENDERING-660
- https://github.com/xwiki/xwiki-rendering/commit/a4ca31f99f524b9456c64150d6f375984aa81ea7
For more information
If you have any questions or comments about this advisory:
- Open an issue in Jira XWiki.org
- Email us at Security Mailing List
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Java / Kotlin (Maven) | org.xwiki.rendering:xwiki-rendering-syntax-xhtml | >= 5.4.5, < 14.10 | 14.10 |
References
- https://github.com/xwiki/xwiki-rendering/security/advisories/GHSA-w3wh-g4m9-783p
- https://nvd.nist.gov/vuln/detail/CVE-2025-53835
- https://github.com/xwiki/xwiki-rendering/commit/a4ca31f99f524b9456c64150d6f375984aa81ea7
- https://github.com/xwiki/xwiki-rendering
- https://jira.xwiki.org/browse/XRENDERING-660
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H- Weakness (CWE)
CWE-79, CWE-80- Platform
- Java / Kotlin (Maven)
- Package
org.xwiki.rendering:xwiki-rendering-syntax-xhtml- Disclosed
- 14.07.2025
- Updated
- 11.10.2026 13:20
Sources and licenses
OSV / GitHub Advisory Database - GHSA-w3wh-g4m9-783p - CC BY 4.0
Vulnerability history: org.xwiki.rendering:xwiki-rendering-syntax-xhtml
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.
- Total entries
- 2
- First → latest
- 05.2023 07.2025
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 2
Disclosures per year
- 2023: 1
- 2024: 0
- 2025: 1
- 2026: 0
-
XWiki Rendering is vulnerable to XSS attacks through insecure XHTML syntax this entry
Know which vulnerabilities affect your application
With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.