CVE-2026-15446

Deferred Deferred - Pending Action

Stored XSS in EWWW Image Optimizer WordPress Plugin

Publication date: 2026-08-19

Last updated on: 2026-08-20

Assigner: Wordfence

Description

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.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-08-19

Last Modified

2026-08-20

Generated

2026-09-08

AI Q&A

2026-08-19

EPSS Evaluated

2026-09-07

NVD

CVE-2026-15446

EUVD

EUVD-2026-62342

Affected Vendors & Products

Vendor	Product	Version / Range
nosilver4u	ewww_image_optimizer	to 8.7.3 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-79	The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Attack-Flow Graph

Executive Summary

This is a Stored Cross-Site Scripting (XSS) vulnerability in the EWWW Image Optimizer WordPress plugin. It allows authenticated attackers with contributor-level access or higher to inject malicious scripts into web pages by exploiting insufficient input sanitization and output escaping in the 'data-script' Lazy Load Attribute feature. The attack involves embedding a crafted img element with a malicious data-script attribute in post content, which then executes scripts when users view the page.

Detection Guidance

Check WordPress sites using EWWW Image Optimizer versions up to 8.7.3 for img elements with class='lazyload' and data-script attributes pointing to external URLs in post content. Review server logs for suspicious script injections or unauthorized script executions.

Impact Analysis

If exploited, this vulnerability could allow attackers to steal user sessions, perform actions on behalf of users, or deface websites. Users visiting an infected page may have their data compromised or be redirected to malicious sites. The impact depends on user privileges; higher-privilege users face greater risks.

Compliance Impact

This vulnerability could lead to unauthorized access to user data, violating GDPR's data protection requirements and HIPAA's security rules for protected health information. Organizations may face fines or penalties for failing to protect user data adequately.

Mitigation Strategies

Update EWWW Image Optimizer to the latest version beyond 8.7.3. Remove any injected img elements with data-script attributes from posts. Implement input sanitization for post content and restrict contributor-level access to trusted users.

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