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MediawikiCMS

CVE-2026-8857

HIGH · 8.8 CVSS v3.1 Published 2026-07-01
Fix available
A fix is available. Upgrade to 1.43.9 / 1.44.6 or later.
See remediation →
94/100
Remediation priority · Urgent
Public exploit Remotely reachable Zero-click 7 weeks old

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
A vulnerability in Wikimedia Foundation timeline. This vulnerability is associated with program files scripts/EasyTimeline.Pl, includes/Timeline.Php. This issue affects timeline: from * before 1.46.0, 1.45.4, 1.44.6, 1.43.9.

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 · moderate confidence

Vulnerability in Wikimedia Foundation's timeline functionality (scripts/EasyTimeline.Pl and includes/Timeline.Php) affecting versions before 1.46.0, 1.45.4, 1.44.6, and 1.43.9. The HIGH severity (CVSS 8.8) suggests potential code injection or command execution in timeline processing scripts.

MitigationUpgrade to version 1.46.0 or later (or to patched versions 1.45.4, 1.44.6, 1.43.9). If upgrading is not immediately possible, restrict access to timeline functionality and review input handling in the affected Perl and PHP files.

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
MediawikiCMS
Affected:>= 1.43.0, < 1.43.9>= 1.44.0, < 1.44.6>= 1.45.0, < 1.45.4

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/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 checks

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

  1. Check MediaWiki version
    Locate the MediaWiki installation directory and find the file 'includes/Defines.php' or 'composer.json' which contains the version constant MW_VERSION or similar version identifier. Alternatively, access /mediawiki/api.php?action=query&meta=siteinfo&siprop=general to retrieve the installed version.
    Affected if The installed version falls within >= 1.43.0, < 1.43.9; >= 1.44.0, < 1.44.6; or >= 1.45.0, < 1.45.4.
  2. Verify Timeline extension is enabled
    Check the MediaWiki configuration file 'LocalSettings.php' for the line 'wfLoadExtension( "Timeline" );' or look for any require_once calls referencing the Timeline extension in the extensions directory.
    Affected if The Timeline extension is loaded or installed in the MediaWiki installation.
  3. Locate Timeline extension files
    Navigate to the 'extensions/Timeline' directory in the MediaWiki installation. Identify the presence of 'scripts/EasyTimeline.pl' or 'includes/Timeline.php' files.
    Affected if The vulnerable files scripts/EasyTimeline.Pl or includes/Timeline.Php exist in the installation.
  4. Check Timeline extension version
    Look for a version file or CHANGELOG within the extensions/Timeline directory, or check the extension's composer.json or extension.json for the version number.
    Affected if The Timeline extension version is below 1.43.9, 1.44.6, or 1.45.4 depending on your MediaWiki branch, or is unpatched.

You are affected if your MediaWiki version is 1.43.0-1.43.8, 1.44.0-1.44.5, or 1.45.0-1.45.3 AND the Timeline extension is enabled with the vulnerable files present.

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
Upgrade available Upgrade to 1.43.9 / 1.44.6 / 1.45.4 or later
Fixed in 1.43.91.44.61.45.4
Interim mitigation

Upgrade to version 1.46.0 or later (or to patched versions 1.45.4, 1.44.6, 1.43.9). If upgrading is not immediately possible, restrict access to timeline functionality and review input handling in the affected Perl and PHP files.

Recommended fix High confidence

Upgrade to MediaWiki 1.46.0 (or minimum fix version for your branch: 1.43.9 for 1.43.x, 1.44.6 for 1.44.x, 1.45.4 for 1.45.x)

  1. 1. Backup your MediaWiki installation and database before upgrading
  2. 2. Download MediaWiki 1.46.0 (or the appropriate fix version for your branch: 1.43.9, 1.44.6, or 1.45.4) from the official MediaWiki releases page
  3. 3. Extract the new version to your web server
  4. 4. Copy your LocalSettings.php configuration file from the old installation to the new installation
  5. 5. Run the update.php maintenance script: php maintenance/update.php
  6. 6. Verify the timeline functionality works correctly after upgrade
  7. 7. Clear any caching systems (e.g., PHP OPcache, CDN caches)
Caveat Minor point release upgrades typically have no breaking changes; always review the release notes before upgrading

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

Fix this in Mediawiki Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
Get the upgrade done

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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-2026-8857 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