How severe is CVE-2026-34151?

No CVSS score has been assigned to CVE-2026-34151 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-34151?

CVE-2026-34151 affects the following packages: org.xwiki.platform:xwiki-platform-oldcore (Maven), org.xwiki.platform:xwiki-platform-oldcore (Maven). Ecosystems affected: Maven.

How do I fix CVE-2026-34151?

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.

How do I detect CVE-2026-34151 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.xwiki.platform:xwiki-platform-oldcore, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-34151 if there is no patch (or I can't update yet)?

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.

Is CVE-2026-34151 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-34151 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-34151?

CVE-2026-34151 has an EPSS (Exploit Prediction Scoring System) score of 1.1%, placing it in the 64th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-34151?

CVE-2026-34151 is classified as CWE-24 (CWE-24). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-34151 published, and has it been updated?

CVE-2026-34151 was published on September 14, 2026 and was last updated on October 2, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕ Maven

Not in CISA KEV

CVE-2026-34151 — xwiki-platform-oldcore

Fix: xwiki/xwiki-commons#1675

CVE-2026-34151 is a CWE-24 vulnerability in org.xwiki.platform:xwiki-platform-oldcore. A fix is available for org.xwiki.platform:xwiki-platform-oldcore — see the affected versions and patch details below.

XWiki Platform: Resource path traversal via /skin/ action endpoint in Jetty 12+

Also known asGHSA-qj4x-9g63-25g6

Published

Sep 14, 2026

Updated

Oct 2, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Oct 12, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-34151.

EPSS Exploitation Probability

via FIRST.org ↗

1.1%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs64th percentile — riskier than 64% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

2 pkgs affected

☕org.xwiki.platform:xwiki-platform-oldcore☕org.xwiki.platform:xwiki-platform-oldcore

Real-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

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.xwiki.platform:xwiki-platform-oldcore`	all versions	17.10.5`org.xwiki.platform:xwiki-platform-oldcore:17.10.5`
☕Maven	`org.xwiki.platform:xwiki-platform-oldcore`	≥ 18.0.0-rc-1&&< 18.2.0	18.2.0`org.xwiki.platform:xwiki-platform-oldcore:18.2.0`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.xwiki.platform:xwiki-platform-oldcore, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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.

Frequently Asked Questions

### 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

O3 Security · Impact-Aware SCA

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