Summary
XWiki Platform has path traversal via resources parameter in ssx and jsx endpoints when using leading slash
Workarounds
There is no known workaround, other than upgrading XWiki.
References
- https://jira.xwiki.org/browse/XCOMMONS-3547
- https://github.com/xwiki/xwiki-commons/commit/a979cafd89f6a9c9c0b9ab19744d672df64429bf
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
Attribution
The vulnerability was reported by Michał Kołek.
Impact
It's possible to get access and read configuration files by using URLs such as http://localhost:8080/bin/ssx/Main/WebHome?resource=/../../WEB-INF/xwiki.cfg&minify=false.
This can apparently be reproduced on Tomcat instances.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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This has been patched in 18.0.0-rc-1, 17.10.3, 17.4.9, 16.10.17.
Frequently Asked Questions
- What is CVE-2026-23734? CVE-2026-23734 is a critical-severity security vulnerability in org.xwiki.commons:xwiki-commons-classloader-api (maven), affecting versions >= 4.2-milestone-2, < 16.10.17. It is fixed in 16.10.17, 17.4.9, 17.10.3, 18.1.0-rc-1.
- Which versions of org.xwiki.commons:xwiki-commons-classloader-api are affected by CVE-2026-23734? org.xwiki.commons:xwiki-commons-classloader-api (maven) versions >= 4.2-milestone-2, < 16.10.17 is affected.
- Is there a fix for CVE-2026-23734? Yes. CVE-2026-23734 is fixed in 16.10.17, 17.4.9, 17.10.3, 18.1.0-rc-1. Upgrade to this version or later.
- Is CVE-2026-23734 exploitable, and should I be worried? Whether CVE-2026-23734 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-23734 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-23734?
- Upgrade
org.xwiki.commons:xwiki-commons-classloader-apito 16.10.17 or later - Upgrade
org.xwiki.commons:xwiki-commons-classloader-apito 17.4.9 or later - Upgrade
org.xwiki.commons:xwiki-commons-classloader-apito 17.10.3 or later - Upgrade
org.xwiki.commons:xwiki-commons-classloader-apito 18.1.0-rc-1 or later
- Upgrade