WordPress security changelog
HIGH CVE-2026-5821 Deferred

Image Optimizer – Optimize Images and Convert to WebP or AVIF: Arbitrary file deletion

Image Optimizer – Optimize Images and Convert to WebP or AVIF is affected by arbitrary file deletion. Exploitation requires at least author-level access. A successful request can remove files outside the intended scope and may make the site unavailable. The published affected range is <= 1.7.4.

CVE / CNA score 8.1 CVSS 3.1 · security@wordfence.com
NVD score Pending NVD has not published its own CVSS assessment.
Component
Image Optimizer – Optimize Images and Convert to WebP or AVIF
Plugin slug
image-optimization
Affected
<= 1.7.4
Safe version
> 1.7.4
Published
Jul 02, 2026
Weakness
CWE-73 — External Control of File Name or Path

This CVE was published Jul 02, 2026 and is one of 2 known issues for this plugin.

What to do

Update, patch or deactivate.

Update Image Optimizer – Optimize Images and Convert to WebP or AVIF to a release after 1.7.4, or disable and remove it until a fixed version is available.

A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.

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.

Source record

Technical description

The Image Optimizer plugin for WordPress is vulnerable to arbitrary file deletion in versions up to and including 1.7.4. This is due to insufficient path validation in the Image_Backup::remove() function where backup file paths stored in post meta are used directly in file deletion operations without verifying they are within the uploads directory. The plugin stores backup file paths in the image_optimizer_metadata post meta field and trusts these paths completely when deleting backups on the delete_attachment hook. An authenticated attacker with Author-level access can edit the image_optimizer_metadata post meta on their own attachments via WordPress's Custom Fields interface, injecting arbitrary absolute file paths into the backups array. When the attacker subsequently deletes the attachment, the plugin calls File_System::delete() on each path without validation. This makes it possible for authenticated attackers, with Author-level access and above, to delete arbitrary files on the server within the web server's filesystem permissions, potentially leading to denial of service, data loss, or security degradation.

CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

References

Primary and upstream sources