dbcve.org
Missing AuthorizationWeakness · CWE-862

CVE-2026-5427

MEDIUM · 5.3 CVSS v3.1 Published 2026-04-17
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
62/100
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
The Kubio plugin for WordPress is vulnerable to Arbitrary File Upload in versions up to and including 2.7.2. This is due to insufficient capability checks in the kubio_rest_pre_insert_import_assets() function, which is hooked to the rest_pre_insert_{post_type} filter for posts, pages, templates, and template parts. When a post is created or updated via the REST API, Kubio parses block attributes looking for URLs in the 'kubio' attribute namespace and automatically imports them via importRemoteFile() without verifying the user has the upload_files capability. This makes it possible for authenticated attackers with Contributor-level access and above to bypass WordPress's normal media upload restrictions and upload files fetched from external URLs to the media library, creating attachment posts in the database.

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

The Kubio WordPress plugin (versions up to 2.7.2) has an arbitrary file upload vulnerability in the kubio_rest_pre_insert_import_assets() function. When posts are created or updated via the REST API, the function parses block attributes for URLs in the 'kubio' attribute namespace and automatically imports them via importRemoteFile() without verifying the user has the upload_files capability. This allows authenticated attackers with Contributor-level access to bypass WordPress media upload restrictions and upload arbitrary files from external URLs to the media library.

MitigationAdd a capability check for 'upload_files' before executing importRemoteFile() in kubio_rest_pre_insert_import_assets(), and restrict which post types the filter hook applies to.

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
None
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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. Verify Kubio plugin is installed and active
    In WordPress admin, go to Plugins > Installed Plugins and look for 'Kubio' or check via wp-cli: wp plugin list --status=active --filter=name=kubio
    Affected if Kubio plugin is installed and active in WordPress
  2. Determine installed Kubio version
    Check the plugin version in the plugin header (Plugins > Installed Plugins > Kubio) or read the main plugin file header at wp-content/plugins/kubio/plugin.php
    Affected if Version is 2.7.2 or lower (any version up to and including 2.7.2)
  3. Confirm vulnerable function exists in codebase
    Search for the function 'kubio_rest_pre_insert_import_assets' in the plugin files, typically in includes/rest/ or similar directories within the kubio plugin folder
    Affected if The function kubio_rest_pre_insert_import_assets() exists in the plugin code
  4. Verify REST API endpoint is accessible to authenticated users
    Test accessing /wp-json/wp/v2/posts with a Contributor-level user account via POST request; WordPress allows contributors to create posts via REST API by default
    Affected if Contributor-level users can access and create/update posts via WordPress REST API
  5. Check if importRemoteFile is called without capability check
    Examine the kubio_rest_pre_insert_import_assets function in the source code for any 'upload_files' capability check before calling importRemoteFile()
    Affected if The code calls importRemoteFile() without first verifying the user has upload_files capability

A user is affected if Kubio plugin versions up to 2.7.2 are installed and active, the vulnerable function exists in the codebase, and Contributor-level users can access the REST API without capability verification on the file import function.

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

Add a capability check for 'upload_files' before executing importRemoteFile() in kubio_rest_pre_insert_import_assets(), and restrict which post types the filter hook applies to.

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
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-5427 — 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-2026-5427 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