XSS in Ewww Image Optimizer

CVE-2026-91011

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 that is stored in published content and executes in the browser of any user who later views the affected page.

Vulnerability class: XSS (Cross-Site Scripting)

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H.

Affected products

  • Unknown Ewww Image Optimizer

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-91011?
CVE-2026-91011 is a medium-severity vulnerability in Ewww Image Optimizer, classified under Cross-site Scripting. CVSS score: 6.8/10. Published 2026-09-17.
How severe is CVE-2026-91011?
Medium severity. CVSS v3 base score is 6.8 out of 10.