CVE-2026-91011 EWWW Image Optimizer CVE debrief

Who should care

Defenders responsible for WordPress installations with the EWWW Image Optimizer plugin, and users with author-level access and above, should assess exposure and prioritize updating the plugin.

Why it matters

The EWWW Image Optimizer WordPress plugin vulnerability allows authenticated users to inject arbitrary JavaScript, which executes in the browser of any user who later views the affected page. Defenders should prioritize verifying and updating the plugin, and assess exposure for users with author-level access and above.

• Potential JavaScript injection attacks on users viewing affected pages
• Exposure for users with author-level access and above

Technical summary

The EWWW Image Optimizer WordPress plugin before 8.7.7 does not properly escape image attribute values when it rewrites page output, allowing authenticated users with author-level access and above to inject arbitrary JavaScript. This vulnerability affects WordPress installations with the EWWW Image Optimizer plugin, particularly those with users having author-level access or higher. Defenders should prioritize verifying and updating the plugin to version 8.7.7 or later, and assess exposure for users with author-level access and above.

Defensive priority

Defenders should prioritize verifying and updating the EWWW Image Optimizer WordPress plugin to version 8.7.7 or later, and assess exposure for users with author-level access and above.

Recommended defensive actions

• Verify and update the EWWW Image Optimizer WordPress plugin to version 8.7.7 or later
• Assess exposure for users with author-level access and above
• Monitor for potential JavaScript injection attacks
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD vulnerability detail page provide information on the vulnerability, but limited details are available on exploitation or impact. The EWWW Image Optimizer plugin vulnerability was publicly disclosed, and defenders should verify plugin versions and assess exposure for users with author-level access and above. Limited source details are available on potential impact or mitigation effectiveness.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.