CVE-2026-34151
Fix: xwiki/xwiki-commons#1675CVE-2026-34151 is a security vulnerability in org.xwiki.platform:xwiki-platform-oldcore. O3 Security confirms whether CVE-2026-34151 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
XWiki Platform Old Core: Resource path traversal via /skin/ action endpoint in Jetty 12+
Real-World Exposure
org.xwiki.platform:xwiki-platform-oldcore☕org.xwiki.platform:xwiki-platform-oldcoreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
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
For more information
If there are any questions or comments about this advisory:
- Open an issue in Jira XWiki.org
- Send an email to the Security Mailing List
Attribution
Lê Ngọc Khoa reported the vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.xwiki.platform:xwiki-platform-oldcore | all versions | 17.10.5 |
| ☕Maven | org.xwiki.platform:xwiki-platform-oldcore | ≥ 18.0.0-rc-1&&< 18.2.0 | 18.2.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.xwiki.platform:xwiki-platform-oldcore. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update org.xwiki.platform:xwiki-platform-oldcore to 17.10.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-34151 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-34151 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-34151. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-34151 in your dependencies?
O3 detects CVE-2026-34151 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.