Blocksy Companion: Dangerous file upload
Blocksy Companion is affected by dangerous file upload. Exploitation requires at least author-level access. Successful exploitation can place attacker-controlled executable content on the server and may lead to full site compromise.
- Component
- Blocksy Companion
- Plugin slug
blocksy-companion- Affected
- See vendor advisory
- Safe version
- See mitigation notes
- Published
- Nov 11, 2025
This CVE was published Nov 11, 2025 and is one of 12 known issues for this plugin.
Update, patch or deactivate.
Update Blocksy Companion to a release outside the affected range, or disable and remove it until a fixed version is available.
No confirmed safe version is listed. Consider a vendor-supported patch or temporarily restricting the affected functionality while you assess the risk.
Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.
Technical description
The Blocksy Companion plugin for WordPress is vulnerable to authenticated arbitrary file upload in all versions up to, and including, 2.1.19. This is due to insufficient file type validation detecting SVG files, allowing double extension files to bypass sanitization while being accepted as a valid SVG file. This makes it possible for authenticated attackers, with author level access and above, to upload arbitrary files on the affected site's server which may make remote code execution possible.
CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H