How to fix CVE-2025-59839?

Within 7 days: Identify all affected systems running versions 4.0.0 and and apply vendor patches promptly. Verify anti-CSRF tokens and content security policies are enforced.

Is Embedvideo affected by CVE-2025-59839?

Organizations using EmbedVideo Extension face significant risk from CVE-2025-59839, a cross-site scripting vulnerability rated CVSS 8.6. Attackers could inject malicious scripts to steal user sessions, credentials, or perform actions on behalf of authenticated users.

CVE-2025-59839

HIGH

2025-09-25 [email protected]

XSS Embedvideo

8.6

CVSS 3.1

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

Low

Availability

Low

Lifecycle Timeline

Analysis Generated

Mar 28, 2026 - 19:14 vuln.today

Patch Released

Mar 28, 2026 - 19:14 nvd

Patch available

PoC Detected

Oct 14, 2025 - 20:02 vuln.today

Public exploit code

CVE Published

Sep 25, 2025 - 14:15 nvd

HIGH 8.6

DescriptionNVD

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. In versions 4.0.0 and prior, the EmbedVideo extension allows adding arbitrary attributes to an HTML element, allowing for stored XSS through wikitext. This issue has been patched via commit 4e075d3.

AnalysisAI

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. Rated high severity (CVSS 8.6), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Technical ContextAI

This vulnerability is classified as Cross-Site Scripting (XSS) (CWE-79), which allows attackers to inject malicious scripts into web pages viewed by other users. 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. In versions 4.0.0 and prior, the EmbedVideo extension allows adding arbitrary attributes to an HTML element, allowing for stored XSS through wikitext. This issue has been patched via commit 4e075d3. Affected products include: Star-Citizen Embedvideo.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Sanitize all user input, use Content-Security-Policy headers, encode output contextually (HTML, JS, URL). Use frameworks with built-in XSS protection.

CVE-2025-59839 vulnerability details – vuln.today

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