What is CVE-2026-0669?

CVE-2026-0669 is a high-severity vulnerability in CSS Project, classified under Path Traversal. CVSS score: 7.5/10. Published 2026-01-07.

How severe is CVE-2026-0669?

High severity. CVSS v3 base score is 7.5 out of 10.

Path Traversal in CSS Project

CVE-2026-0669

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Wikimedia Foundation MediaWiki - CSS extension allows Path Traversal.This issue affects MediaWiki - CSS extension: 1.44, 1.43, 1.39.

Vulnerability class: Path Traversal (Directory Traversal)

Published 2026-01-07 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (34.9th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000

Affected products

CSS Project
MediaWiki — versions 1.39.0, 1.43.0, 1.44.0
Wikimedia Foundation MediaWiki - CSS Extension — versions 1.44, 1.43, 1.39

Weakness classification (CWE)

CWE-22 — Path Traversal

References

c4f26cc8-17ff-4c99-b5e2-38fc1793eacc (Exploit, Issue Tracking)
c4f26cc8-17ff-4c99-b5e2-38fc1793eacc (Patch)

Frequently asked questions

What is CVE-2026-0669?: CVE-2026-0669 is a high-severity vulnerability in CSS Project, classified under Path Traversal. CVSS score: 7.5/10. Published 2026-01-07.
How severe is CVE-2026-0669?: High severity. CVSS v3 base score is 7.5 out of 10.