CVE-2026-57440

Mediawiki EmbedVideo Extension has stored XSS via malformed src url with $wgEmbedVideoRequireConsent disabled

Published Sep 24, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
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, with $wgEmbedVideoRequireConsent disabled (not the default), the urls for videos are passed into an iframe src attribute without sanitization. When given a malformed url or id, the src attribute can be escaped via double quotes, allowing for html/javascript injection. Version 4.1.0 contains a patch.

Analysis

AI-generated

Technical impact

The EmbedVideo extension processes a parser function and tags that embed videos from various services. When the configuration setting $wgEmbedVideoRequireConsent is set to false, the URL or identifier supplied to the extension is inserted directly into an iframe src attribute without sanitization. A malformed URL that contains a quote character can terminate the src attribute and inject arbitrary HTML or JavaScript. This behavior results in a stored cross‑site scripting vulnerability, allowing an attacker who can edit a page to plant malicious script that will execute in the browsers of any user who views the page.

Affected Systems

StarCitizenWiki’s MediaWiki installation running the mediawiki-extensions-EmbedVideo prior to version 4.1.0, when the site configuration disables the consent requirement. Only installations using earlier releases are affected; versions 4.1.0 and later contain a patch.

Risk and Exploitability

With a CVSS score of 7.5 the vulnerability is considered high severity. The EPSS score is not available and the vulnerability is not currently catalogued in CISA KEV. Because the flaw requires a page edit, the attack vector is likely social‑engineering or exploitation of an existing privileged editor. Once injected, the malicious payload is stored in the page content and will execute for all viewers, providing an attacker with a persistent injection that can steal credentials or deface the site.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade the EmbedVideo extension to v4.1.0 or later, which sanitizes the src attribute.
  • Review the $wgEmbedVideoRequireConsent setting; set it to true to enforce user confirmation of embedded videos and prevent accidental injection when the extension is old.
  • Restrict page editing privileges to trusted users and monitor the use of #ev and <ev> tags for suspicious input.

Generated by OpenCVE AI on September 25, 2026 at 05:34 UTC.

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-v65j-hff3-753c Mediawiki EmbedVideo Extension has stored XSS via malformed src url with $wgEmbedVideoRequireConsent disabled
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Starcitizenwiki
Starcitizenwiki mediawiki-extensions-embedvideo
Vendors & Products Starcitizenwiki
Starcitizenwiki mediawiki-extensions-embedvideo
Type Values Removed Values Added
Description 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, with $wgEmbedVideoRequireConsent disabled (not the default), the urls for videos are passed into an iframe src attribute without sanitization. When given a malformed url or id, the src attribute can be escaped via double quotes, allowing for html/javascript injection. Version 4.1.0 contains a patch.
Title Mediawiki EmbedVideo Extension has stored XSS via malformed src url with $wgEmbedVideoRequireConsent disabled
Weaknesses CWE-79
CWE-80
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'}

Weaknesses
  • CWE-79

    Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

  • CWE-80

    Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 29, 2026, 3:09 AM
Reserved
Jun 24, 2026, 1:21 PM
Status
Deferred
Published
Sep 24, 2026, 7:17 PM
Modified
Sep 30, 2026, 7:57 PM