CVE-2026-0669

HighPublic PoC

Published: 07 January 2026

Published

07 January 2026

Modified

23 February 2026

KEV Added

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Patch

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CVSS Score 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS Score 0.0009 25.1th percentile

Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-0669 is a high-severity Path Traversal (CWE-22) vulnerability in Mediawiki Mediawiki. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 25.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique.

Threat & Defense Details

Likely Mitigating ControlsAI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SI-10 Information Input Validation

addresses: CWE-22

Validates pathnames and filenames to prevent traversal outside intended directories.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

T1005 Data from Local System Collection

Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.

attack.mitre.org →

Why these techniques?

Path traversal in public-facing MediaWiki extension enables remote unauthenticated file read (T1190 initial access + T1005 local data disclosure).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

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.

Deeper analysisAI

CVE-2026-0669 is an Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability, classified as CWE-22, in the CSS extension for Wikimedia Foundation's MediaWiki. The issue affects versions 1.44, 1.43, and 1.39 of the MediaWiki CSS extension and was published on 2026-01-07.

The vulnerability carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N), meaning it is exploitable remotely over the network by unauthenticated attackers (PR:N) with low attack complexity and no user interaction. Attackers can traverse path restrictions to access files outside intended directories, resulting in high confidentiality impact through unauthorized data disclosure, while integrity and availability remain unaffected.

Advisories and patches are detailed in the Gerrit change at https://gerrit.wikimedia.org/r/q/Ia15bf3f2e5a341868568492a736ac3dbf706c22e and the Phabricator task at https://phabricator.wikimedia.org/T401526.