CVE-2026-34151
highpriority · track · 0EPSS 0.011 · 64 %ileDEUSEPSS · scored 2026-10-27
XWiki Platform is a generic wiki platform. Prior to 17.10.5 and 18.2.0, the /skin/ action in com.xpn.xwiki.web.SkinAction can resolve double-encoded parent-directory segments outside the intended skin or web-application resource prefix when Jetty 12 or later decodes the request path. The affected lookup is replaced with Environment.getResourceAsStream(String, String), which constrains a resource to its expected prefix. An unauthenticated remote attacker can use the vulnerable behavior to read arbitrary resources permitted to the Jetty process, including WEB-INF/xwiki.cfg and, depending on deployment depth and operating-system permissions, host files. Tomcat and Jetty versions before 12 do not appear affected. This issue is fixed in versions 17.10.5 and 18.2.0.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.6–8.2
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (6)
Products and version ranges known to be affected.
- Maven org.xwiki.platform:xwiki-platform-oldcore< 17.10.5osvUSpkg:maven/org.xwiki.platform/xwiki-platform-oldcore
- Maven org.xwiki.platform:xwiki-platform-oldcore18.0.0-rc-1 → 18.2.0osvUSpkg:maven/org.xwiki.platform/xwiki-platform-oldcore
advisories (2)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-2224xwiki: Schwachstelle ermöglicht Offenlegung von InformationenDeutsch2026-07-06csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann eine Schwachstelle in xwiki ausnutzen, um Informationen offenzulegen.
- GHSA-qj4x-9g63-25g6XWiki Platform Old Core: Resource path traversal via /skin/ action endpoint in Jetty 12+2026-07-07ghsa · osvUS
### Impact With Jetty 12+ a user can craft a URL to access any resource the Jetty instance is allowed to access. For example `http://[host]/xwiki/bin/skin/..%252f/..%252f..%252f..%252f..%252f..%252f..%252f..%252fetc/passwd` allows downloading the content of the /etc/passwd file, provided Jetty is allowed to read it, and if your XWiki webapp is located exactly 5 levels below `/` (like `/var/lib/jetty/webapps/xwiki`, which is the case in the docker image, for example). Another example which does not go out of the XWiki webapp, but it's still a vulnerability (since users should not be allowed to access Hibernate or XWiki configuration files) is `http://[host]/xwiki/bin/skin/..%252f/..%252fWEB-INF/xwiki.cfg`. ### Patches This vulnerability has been patched in XWiki 17.10.5 and 18.2.0. ### Workarounds A possible workaround is to use a different application server, like Jetty < 12 (in the case of XWiki < 17) or Tomcat, which don't seem to be impacted. ### Resources * https://jira.xwiki.org/browse/XWIKI-24075 * https://jira.xwiki.org/browse/XCOMMONS-3594 ### For more information If there are any questions or comments about this advisory: * Open an issue in [Jira XWiki.org](https://jira.xwiki.org/) * Send an email to the [Security Mailing List](mailto:security@xwiki.org) ### Attribution Lê Ngọc Khoa reported the vulnerability.
also known as (1)
Other names and identifiers for this entity.
sources
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references (9)
External citations — patches, advisories, analysis.
- https://www.xwiki.org/xwiki/bin/view/ReleaseNotes/Data/XWiki/18.2.0/Patchcnnvd
- https://github.com/xwiki/xwiki-commons/pull/1675nvd
- https://github.com/xwiki/xwiki-platform/commit/79eba8655f3a96021a8e7ad07956e48d20a82383nvd
- https://github.com/xwiki/xwiki-platform/commit/f7b33704083d3b4e45d1b9fc1e2cc33c66855f85nvd
- https://github.com/xwiki/xwiki-platform/releases/tag/xwiki-platform-17.10.5nvd
- https://github.com/xwiki/xwiki-platform/releases/tag/xwiki-platform-18.2.0nvd
- https://github.com/xwiki/xwiki-platform/security/advisories/GHSA-qj4x-9g63-25g6nvd
- https://jira.xwiki.org/browse/XCOMMONS-3594nvd
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