dbcve.org
Improper Input ValidationWeakness · CWE-20

CVE-2025-53502

MEDIUM · 6.5 CVSS v3.1 Published 2025-07-03
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
74/100
Remediation priority · Elevated
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 Input Validation vulnerability in Wikimedia Foundation Mediawiki - FeaturedFeeds Extension allows Cross-Site Scripting (XSS).This issue affects Mediawiki - FeaturedFeeds Extension: 1.39.X, 1.42.X, 1.43.X.

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

Cross-Site Scripting (XSS) vulnerability in MediaWiki's FeaturedFeeds Extension caused by improper input validation. The vulnerability allows injection of malicious scripts through feed content due to insufficient sanitization of user-supplied or feed-sourced data.

MitigationUpdate MediaWiki to patched versions (1.39.x, 1.42.x, 1.43.x) that address this vulnerability, or apply available patches for the FeaturedFeeds extension with proper input validation and output encoding.

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
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

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

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. Identify MediaWiki installation and version
    Check the file 'includes/Defines.php' for the MW_VERSION constant, or look for 'LocalSettings.php' and run 'php maintenance/showLowPrioritySQL.php' if available, or check your package manager for mediawiki version
    Affected if Version is unpatched (pre-fix releases of 1.39.x, 1.42.x, or 1.43.x)
  2. Confirm FeaturedFeeds extension is enabled
    Search for 'FeaturedFeeds' in your 'LocalSettings.php' configuration file or check the 'extensions/FeaturedFeeds' directory exists and contains extension code
    Affected if FeaturedFeeds extension is loaded in the MediaWiki configuration
  3. Check for the input validation fix in FeaturedFeeds code
    Examine the file 'extensions/FeaturedFeeds/includes/FeaturedFeed.php' and look for input sanitization functions such as 'htmlspecialchars()', 'Xml::escapeJsPtr()', or similar output encoding applied to feed content variables
    Affected if No proper input validation or output encoding is present for feed-sourced data in the FeaturedFeed code
  4. Verify MediaWiki version against affected ranges
    Compare your installed version number to the known vulnerable range: unpatched 1.39.x, 1.42.x, 1.43.x releases. Patched versions contain the security fix for CVE-2025-53502
    Affected if Running an unpatched MediaWiki version within the 1.39.x, 1.42.x, or 1.43.x release lines

A user is affected if they run an unpatched MediaWiki version (1.39.x/1.42.x/1.43.x before the CVE fix) with the FeaturedFeeds extension enabled and lack proper input sanitization in the feed handling code.

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

Update MediaWiki to patched versions (1.39.x, 1.42.x, 1.43.x) that address this vulnerability, or apply available patches for the FeaturedFeeds extension with proper input validation and output encoding.

Recommended fix Moderate confidence

Latest stable MediaWiki release (1.44.x or higher) which contains the fix for CVE-2025-53502

  1. Check your current MediaWiki version by viewing the version number on Special:Version
  2. Backup your database and files before upgrading
  3. Follow MediaWiki upgrade procedure: upload new files, run update.php (php maintenance/update.php)
  4. Clear any caches after upgrade
  5. Test the FeaturedFeeds extension functionality after upgrade
  6. Verify the fix by checking if the XSS vulnerability is resolved in the FeaturedFeeds output
Caveat Review MediaWiki release notes for any breaking changes between your current version and the target version; may require testing extensions for compatibility

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

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
Get help mitigating

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Scan for this in your stack

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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-2025-53502 in production — separate from our analysis above.

No notes yet

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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