CVE-2021-46147
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 · uneditedAn issue was discovered in MediaWiki before 1.35.5, 1.36.x before 1.36.3, and 1.37.x before 1.37.1. MassEditRegex allows CSRF.
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 confidenceCSRF vulnerability in MediaWiki's MassEditRegex extension allows attackers to trick authenticated administrators into performing unintended wiki modifications by leveraging cross-site request forgery. The vulnerability stems from missing or improper anti-CSRF token validation in the MassEditRegex functionality.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 1.35.5>= 1.36.0, < 1.36.3>= 1.37.0, < 1.37.1CVSS 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
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
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 checksWork through these to decide whether this CVE applies to you.
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Identify the installed MediaWiki versionAccess the Special:Version page on your wiki (usually at /wiki/Special:Version) or check the includes/Defines.php file in your MediaWiki installation directory for the MW_VERSION constantAffected if The installed version is less than 1.35.5, or between 1.36.0 and 1.36.3, or between 1.37.0 and 1.37.1
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Verify if the MassEditRegex extension is installedCheck your LocalSettings.php file for a line containing 'wfLoadExtension' or 'require_once' that references MassEditRegex, or check the extensions/ directory for a MassEditRegex folderAffected if The MassEditRegex extension is loaded in your MediaWiki configuration
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Confirm the extension is enabled for useCheck if the extension is listed as active on Special:Version, or verify that administrators have access to the special page provided by MassEditRegex (typically Special:MassEditRegex)Affected if The MassEditRegex extension is installed and active on the wiki
Your wiki is affected if it runs a vulnerable MediaWiki version (below 1.35.5, 1.36.x before 1.36.3, or 1.37.x before 1.37.1) AND has the MassEditRegex extension installed and enabled.
Generated from the published advisory. Verify against your own configuration.
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 · scoped1.35.51.36.31.37.1
Upgrade MediaWiki to version 1.35.5, 1.36.3, 1.37.1, or later to apply the security patch that adds proper CSRF token validation to the MassEditRegex feature.
1.35.5, 1.36.3, or 1.37.1 (select based on your current branch)
- Back up your MediaWiki database and configuration files
- Determine your current MediaWiki branch (1.35.x, 1.36.x, or 1.37.x)
- Download the appropriate fixed version: 1.35.5+ for 1.35 branch, 1.36.3+ for 1.36 branch, or 1.37.1+ for 1.37 branch
- Replace the MediaWiki files with the new version, preserving your LocalSettings.php and any custom configuration
- Run the maintenance/update.php script to apply any database schema changes
- Clear any caching systems (e.g., PHP opcache, CDN caches)
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,272.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-46147 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-46147 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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