---
id: CVE-2026-39840
title: >-
  Improper neutralization of input during web page generation ('cross-site
  scripting') vulnerability in Wikimedia Foundation Mediawiki - Cargo Extension
  allows XSS Targeting Non-Script Elements.This issue affects Mediawiki - Cargo
  Extensio…
summary: >-
  Improper neutralization of input during web page generation ('cross-site
  scripting') vulnerability in Wikimedia Foundation Mediawiki - Cargo Extension
  allows XSS Targeting Non-Script Elements.This issue affects Mediawiki - Cargo
  Extensio…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
vendor: mediawiki
product: cargo
affected:
  - cargo < 3.8.7
patched:
  - cargo 3.8.7
published: '2026-04-07'
updated: '2026-07-24'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-39840'
references:
  - url: 'https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Cargo/+/1237966'
    label: c4f26cc8-17ff-4c99-b5e2-38fc1793eacc
  - url: 'https://phabricator.wikimedia.org/T416368'
    label: c4f26cc8-17ff-4c99-b5e2-38fc1793eacc
tags:
  - nvd
epss: 0.00158
epssPercentile: 0.05352
ingestedAt: '2026-07-25T23:05:57.975Z'
---

## Overview

Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Wikimedia Foundation Mediawiki - Cargo Extension allows XSS Targeting Non-Script Elements.This issue affects Mediawiki - Cargo Extension: before 3.8.7.

## Affected

- `cargo < 3.8.7`

## Remediation

Upgrade past the affected range:

- `cargo 3.8.7`