CVE-2026-109990
Received Received - Intake

Stored XSS in Flying Scripts WordPress Plugin

Publication date: 2026-10-16

Last updated on: 2026-10-16

Assigner: Wordfence

Description
The Flying Scripts: Delay JavaScript to Improve Site Speed & Performance plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'comment' parameter in all versions up to, and including, 1.2.4 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The exploit bypasses WordPress core's save-time kses sanitization entirely because the payload uses only kses-allowed elements — an <abbr title> attribute and <code> text content — and the XSS is introduced post-save when the plugin's output-buffer rewriter substitutes a double-quote-bearing <code> body into the <abbr title> attribute via predictable, unsalted ___noise___ placeholder keys.

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Meta Information

Published
2026-10-16
Last Modified
2026-10-16
Generated
2026-10-16
AI Q&A
2026-10-16
EPSS Evaluated
N/A
NVD
CVE-2026-109990
EUVD
EUVD-2026-102612

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
gijo Flying Scripts: Delay JavaScript to Improve Site Speed & Performance 0

Helpful Resources

Exploitability

CWE
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KEV
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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.

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Executive Summary

This vulnerability is a Stored Cross-Site Scripting (XSS) flaw in the Flying Scripts plugin for WordPress. It allows unauthenticated attackers to inject malicious scripts via the 'comment' parameter. The issue occurs due to insufficient input sanitization and output escaping in versions up to 1.2.4. Attackers can execute arbitrary web scripts on pages visited by users.

Detection Guidance

Check WordPress sites for the Flying Scripts plugin versions up to 1.2.4. Inspect pages for injected scripts in comments or attributes. Use tools like WP-CLI to list plugins and grep for vulnerable versions.

Impact Analysis

Unauthenticated attackers could inject malicious scripts into your WordPress site. When users visit an affected page, the injected scripts execute, potentially stealing sensitive data like cookies or session tokens. This could lead to account takeovers or unauthorized actions on behalf of users.

Compliance Impact

This vulnerability could lead to data breaches, violating GDPR and HIPAA requirements for protecting user data. If exploited, it may result in unauthorized access to personal or health information, leading to legal penalties and reputational damage.

Mitigation Strategies

Update the Flying Scripts plugin to the latest version. Remove suspicious comments or scripts from pages. Implement strict input validation for user-generated content.

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