dbcve.org
Cross-site Scripting (XSS)Weakness · CWE-79

CVE-2026-39936

MEDIUM · 6.9 CVSS v4.0 Published 2026-04-07
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
78/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in The Wikimedia Foundation Mediawiki - Score Extension allows Cross-Site Scripting (XSS). The issue has been remediated on the `master` branch, and in the release branches for MediaWiki versions 1.43, 1.44, and 1.45.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This is a Cross-Site Scripting (XSS) vulnerability in the MediaWiki Score extension where user-supplied input is not properly neutralized before being rendered in web pages, allowing injection of malicious scripts.

MitigationUpgrade MediaWiki to versions 1.43, 1.44, or 1.45 (or later) which contain the patched Score extension, or apply the fix from the master branch.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/E:X/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:X/AU:X/R:X/V:X/RE:X/U:X

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify Score extension is installed
    Check your MediaWiki extensions directory for the Score extension folder, or look for 'wfLoadExtension( 'Score' )' in your LocalSettings.php file
    Affected if Score extension is installed and enabled in MediaWiki
  2. Confirm Score extension is actively loaded
    Look in your MediaWiki LocalSettings.php file for the extension loading line: wfLoadExtension( 'Score' ) or similar require/include statement for Score
    Affected if The extension is loaded/enabled in the wiki configuration
  3. Check MediaWiki core version
    Navigate to Special:Version on your wiki or check the include/version.php file in your MediaWiki installation directory
    Affected if MediaWiki version is older than 1.43, 1.44, or 1.45 (all affected before patches)
  4. Verify Score functionality is publicly accessible
    Check if anonymous or authenticated users can access pages that use the Score extension syntax (e.g., <score> tags) or any user-contributed content that gets rendered through the extension
    Affected if User-supplied content can be processed and displayed through the Score extension to other users

Your wiki is affected if the Score extension is installed and enabled, and your MediaWiki version is 1.42 or earlier, and users can submit content that gets processed by the Score extension.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade MediaWiki to versions 1.43, 1.44, or 1.45 (or later) which contain the patched Score extension, or apply the fix from the master branch.

Recommended fix Moderate confidence

MediaWiki 1.45 (or 1.44 or 1.43)

  1. Identify your current MediaWiki version by checking the includes/Defines.php file or the Special:Version page
  2. Review the MediaWiki Score extension release notes for version compatibility
  3. Upgrade MediaWiki to version 1.43, 1.44, or 1.45 (whichever is the latest stable in your release line)
  4. Ensure the Score extension is also updated to the corresponding version that matches your MediaWiki upgrade
  5. Clear any caches (e.g., objectcache, parsercache) after upgrading
  6. Verify the upgrade by testing the Score extension functionality
Caveat Review MediaWiki release notes for your target version for any configuration or compatibility changes

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing3.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,750
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-39936 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-39936 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data