0.3
LOW CVSS 4.0
CVE-2026-103439
Various rawParams() and escaped() updates to prevent XSS in Wikibase extension
Description

Improper neutralization of Script-Related HTML tags in a web page (basic XSS) vulnerability in The Wikimedia Foundation MediaWiki Wikbase extension allows Cross-Site Scripting (XSS). This issue affects MediaWiki Wikbase extension: 1.46, 1.45, and 1.43.

INFO

Published Date :

Sept. 30, 2026, 6:18 p.m.

Last Modified :

Sept. 30, 2026, 7:05 p.m.

Remotely Exploit :

No

Source :

c4f26cc8-17ff-4c99-b5e2-38fc1793eacc
Affected Products

The following products are affected by CVE-2026-103439 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 LOW c4f26cc8-17ff-4c99-b5e2-38fc1793eacc
CVSS 4.0 LOW c4f26cc8-17ff-4c99-b5e2-38fc1793eacc
Solution
Update the MediaWiki Wikbase extension to a patched version to fix XSS.
  • Update MediaWiki Wikbase extension to version 1.47 or later.
  • Apply vendor-supplied security patches.
  • Validate input for script-related HTML tags.
  • Sanitize all user-supplied content.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-103439.

URL Resource
https://gerrit.wikimedia.org/r/q/Ie7a35b211565148e0cae437a4a8c41633b81f1b3
https://phabricator.wikimedia.org/T182213
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-103439 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-103439 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-103439 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-103439 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by c4f26cc8-17ff-4c99-b5e2-38fc1793eacc

    Sep. 30, 2026

    Action Type Old Value New Value
    Added Description Improper neutralization of Script-Related HTML tags in a web page (basic XSS) vulnerability in The Wikimedia Foundation MediaWiki Wikbase extension allows Cross-Site Scripting (XSS). This issue affects MediaWiki Wikbase extension: 1.46, 1.45, and 1.43.
    Added CVSS V4.0 AV:L/AC:H/AT:P/PR:H/UI:P/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:N/AU:Y/R:U/V:D/RE:M/U:Amber
    Added CWE CWE-80
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/103xxx/CVE-2026-103439.json">CVE-2026-103439</a>
    Added Reference https://gerrit.wikimedia.org/r/q/Ie7a35b211565148e0cae437a4a8c41633b81f1b3
    Added Reference https://phabricator.wikimedia.org/T182213
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.