---
id: CVE-2026-55691
title: >-
  The EmbedVideo Extension is a MediaWiki extension which adds a parser function
  called #ev and various parser tags for embedding video clips from various
  video sharing services
summary: >-
  The EmbedVideo Extension is a MediaWiki extension which adds a parser function
  called #ev and various parser tags for embedding video clips from various
  video sharing services. Prior to 4.1.0, EmbedHtmlFormatter::toHtml in
  includes/Embed…
severity: high
cvss: 8.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L'
cwe:
  - CWE-79
  - CWE-80
vendor: StarCitizenWiki
product: mediawiki-extensions-EmbedVideo
affected:
  - mediawiki-extensions-EmbedVideo < 4.1.0
patched:
  - starcitizenwiki/embedvideo 4.1.0
published: '2026-09-15'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T16:17:10.127'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55691'
references:
  - url: >-
      https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/commit/370156335b325bb81d14d89edf0a1f2643d50a84
    label: security-advisories@github.com
  - url: >-
      https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/releases/tag/v4.1.0
    label: security-advisories@github.com
  - url: >-
      https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/security/advisories/GHSA-7h5p-637f-jfr7
    label: security-advisories@github.com
  - url: >-
      https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/security/advisories/GHSA-7h5p-637f-jfr7
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/advisories/GHSA-7h5p-637f-jfr7'
tags:
  - nvd
  - cve.org
  - exploit-available
  - ghsa
  - composer
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-16T15:44:19.616396Z'
ecosystem: composer
ingestedAt: '2026-06-22T13:35:24.377Z'
epss: 0.00484
epssPercentile: 0.3924
---

## Overview

The EmbedVideo Extension is a MediaWiki extension which adds a parser function called #ev and various parser tags for embedding video clips from various video sharing services. Prior to 4.1.0, EmbedHtmlFormatter::toHtml in includes/EmbedService/EmbedHtmlFormatter.php passes the user-supplied class value directly to sprintf while constructing a figure element. A quote in the class value can terminate the class attribute and inject arbitrary HTML attributes or markup into the rendered page. A user able to edit a wiki page can store JavaScript that executes for visitors who render the affected content. This issue is fixed in version 4.1.0.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-55691)

Affected packages:

- `starcitizenwiki/embedvideo <= 4.0.0`

Patched in:

- `starcitizenwiki/embedvideo 4.1.0`

Source: https://github.com/advisories/GHSA-7h5p-637f-jfr7