CVE-2026-91051: Unknown Ewww Image Optimizer

Medium severity, CVSS 6.6. EPSS: 0.4% chance of exploitation in the next 30 days.

The EWWW Image Optimizer WordPress plugin before 8.8.0 does not prevent authenticated users with author-level permissions from storing a serialized value in a post meta field that is deserialized when the post is rendered, allowing them to perform PHP Object Injection, which can lead to remote code execution when a suitable gadget chain is present via another installed EWWW Image Optimizer WordPress plugin before 8.8.0 or .

Affected products

• Unknown Ewww Image Optimizer: from 8.6.0, before 8.8.0 (fixed in 8.8.0)

Published 2026-09-30. Last modified 2026-09-30.