CVE-2026-109990 Details
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.
A stored cross-site scripting vulnerability has been identified in the Flying Scripts: Delay JavaScript to Improve Site Speed & Performance plugin for WordPress, affecting all versions through 1.2.4. The vulnerability arises from inadequate input sanitization and output escaping, allowing unauthenticated attackers to inject arbitrary scripts into pages. These scripts execute when a user accesses the compromised page. The exploitation bypasses WordPress's built-in sanitization because the injected payloads utilize elements and attributes that are normally permitted, such as an 'abbr' title attribute and 'code' text content. The cross-site scripting is introduced after the content is saved, as the plugin's output-buffer rewriter replaces double-quote-containing 'code' bodies into 'abbr' title attributes using predictable, unsalted placeholder keys.
Users are advised to update the Flying Scripts WordPress plugin to version 1.2.5 or a later patched version.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Oct 16, 2026CISA-ADP
Assessed Oct 16, 2026References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-79 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Flying Scripts | <= 1.2.4 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Oct 16, 2026 | CVE Modified | CISA-ADP |
| Oct 16, 2026 | New CVE Received | [email protected] |