CVE-2026-34151

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure.

Exploit odds

2.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-09-14 18:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-30 19:57 UTC Last updatedMost recent change to the record

Details

Published

2026-09-14 18:17 UTC

Last modified

2026-09-30 19:57 UTC

Exploit probability

2.5% · EPSS, next 30 days

Weakness

CWE-24

Record status

Deferred

Attack profile CVSS 4.0 · 8.2

Attack vector

Network

Complexity

Low

Attack requirements

Present

Privileges needed

None

User interaction

None

Confidentiality

High

Integrity

None

Availability

None