CVE intelligence and bounded remediation

CVE-2026-5821 — The Image Optimizer plugin for WordPress is vulnerable to arbitrary file deletion in versions up to and including 1.7.4

High CVSS 8.1

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.

Severity
High
CVSS
8.1 (3.1)
Published
2026-07-02
CISA KEV
Not currently listed
Ecosystem
php/wordpress
Weaknesses
CWE-73

Affected products

No browser-safe affected-product rows are available.

Matched remediation archetype

Path traversal, unsafe upload, and file handling

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
  • Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
  • Review canonicalization and containment checks across supported operating systems and storage backends.

Remediate safely

  • Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
  • Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
  • Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.