CWE-1284Weakness · CWE-1284

CVE-2026-27384

CRITICAL · 9.0 CVSS v3.1 Published 2026-03-05
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
99/100
Remediation priority · Urgent
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 Validation of Specified Quantity in Input vulnerability in BoldGrid W3 Total Cache w3-total-cache allows Accessing Functionality Not Properly Constrained by ACLs.This issue affects W3 Total Cache: from n/a through <= 2.9.1.

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

The vulnerability involves improper validation of input quantities in W3 Total Cache that allows attackers to access functionality not properly constrained by access control lists (ACLs). This improper input validation enables authorization bypass, potentially allowing unauthorized users to access privileged functions or administrative features of the caching plugin.

MitigationUpgrade W3 Total Cache to the latest version to obtain patches for this ACL bypass vulnerability. If immediate patching is not possible, restrict administrative interface access to trusted IP addresses and implement additional authentication layers.

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
High
Privileges
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/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. Identify W3 Total Cache plugin version
    Navigate to WordPress admin dashboard > Plugins > Installed Plugins > W3 Total Cache and view the version number displayed under the plugin name. Alternatively, check the plugin's main PHP file header or readme.txt for the Version field.
    Affected if The installed version is any version prior to the patched release (compare to the vendor's security advisory for the fixed version number)
  2. Verify the quantity parameter feature is accessible
    Inspect the W3 Total Cache settings pages, particularly any functionality related to caching, bandwidth limits, or resource allocation where a 'quantity' or 'limit' parameter could be specified in requests.
    Affected if The plugin has features that accept quantity/limit parameters and these are accessible to lower-privileged users
  3. Review user role capabilities
    Go to WordPress admin > Users > Roles or use a role management plugin to examine what capabilities are assigned to subscriber, contributor, author, and editor roles. Check if W3 Total Cache-related capabilities are improperly granted to non-administrator roles.
    Affected if Non-administrator user roles have been granted W3 Total Cache administrative capabilities
  4. Check for unauthorized cache operations
    Review server access logs (Apache error.log, nginx error.log) for requests to /wp-content/w3tc/ or admin-ajax.php with cache-related actions that may have originated from unauthenticated or low-privileged users.
    Affected if Cache modification or purge requests are logged from non-admin users

A user is affected if they have W3 Total Cache installed with any version that has not been patched for this input validation and ACL bypass vulnerability, and the plugin's quantity-related features are accessible to users with insufficient privileges.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade W3 Total Cache to the latest version to obtain patches for this ACL bypass vulnerability. If immediate patching is not possible, restrict administrative interface access to trusted IP addresses and implement additional authentication layers.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-27384 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-27384 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
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