XSS in Nosilver4u Ewww Image Optimizer

CVE-2026-15446

The EWWW Image Optimizer plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'data-script' Lazy Load Attribute in Post Content in all versions up to, and including, 8.7.3 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The exploit is achieved by embedding a crafted img element with class='lazyload' and a data-script attribute pointing to an attacker-controlled URL in post content, which the plugin's bundled lazysizes ls.unveilhooks addon then uses to dynamically create and insert a script element into the DOM at page view time.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (33.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 33.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-15446: held from 0.002 to 0.004.

EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-15446?
CVE-2026-15446 is a medium-severity vulnerability in Nosilver4u Ewww Image Optimizer, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-08-19.
How severe is CVE-2026-15446?
Medium severity. CVSS v3 base score is 6.4 out of 10.