Vulnerability in WP Compress – Instant Performance & Speed Optimization — CVE-2026-120551
What to do now
Update WP Compress – Instant Performance & Speed Optimization to 7.22.38 or later.
Affected versions
- Everything up to and including 7.22.01
Affected: WP Compress – Instant Performance & Speed Optimization (plugin, wp-compress-image-optimizer)
What the vulnerability is
The WP Compress – Instant Performance & Speed Optimization plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 7.22.01. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for unauthenticated attackers to link the victim site to an attacker-controlled WP Compress account, overwrite plugin settings to an aggressive live-CDN preset, and gain the shared api_key that authenticates all nopriv HMAC-gated endpoints — enabling full control over cache purging, file deletion, opcode cache invalidation, and other privileged plugin operations. This vulnerability only affects fresh installations or lite/free-mode installs where no api_key is already stored, as the sole guard fails open when the stored key is absent.
Sources
- https://plugins.trac.wordpress.org/browser/wp-compress-image-optimizer/tags/7.21.27/classes/connect.class.php#L103
- https://plugins.trac.wordpress.org/browser/wp-compress-image-optimizer/tags/7.21.27/classes/mainwp.class.php#L29
- https://plugins.trac.wordpress.org/browser/wp-compress-image-optimizer/tags/7.21.27/classes/mainwp.class.php#L9
- https://plugins.trac.wordpress.org/changeset?reponame=&old=3680035%40wp-compress-image-optimizer&new=3680035%40wp-compress-image-optimizer
- https://www.wordfence.com/threat-intel/vulnerabilities/id/42d4ec8b-d3ed-4aa3-a8b9-cddaf64a7531?source=cve