Flying Scripts: Delay JavaScript to Improve Site Speed & Performance <= 1.2.4 - Unauthenticated Stored Cross-Site Scripting via Comment Content
Summary
| CVE | CVE-2026-109990 |
|---|---|
| State | PUBLISHED |
| Assigner | Wordfence |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-16 04:18:26 UTC |
| Updated | 2026-10-16 04:18:26 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 7.2 HIGH from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Problem Types: CWE-79 | CWE-79 CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 7.2 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
| 3.1 | CNA | DECLARED | 7.2 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
ChangedConfidentiality
LowIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Gijo | Flying Scripts Delay JavaScript To Improve Site Speed Performance | affected 1.2.4 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| plugins.trac.wordpress.org/browser/flying-scripts/tags/1.2.4/lib/dom-parser.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/flying-scripts/tags/1.2.4/html-rewrite.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/flying-scripts/tags/1.2.4/lib/dom-parser.php | [email protected] | plugins.trac.wordpress.org | |
| www.wordfence.com/threat-intel/vulnerabilities/id/0ddc518c-02a0-46a5-93e9-0d92a... | [email protected] | www.wordfence.com | |
| plugins.trac.wordpress.org/browser/flying-scripts/tags/1.2.4/lib/dom-parser.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/flying-scripts/tags/1.2.4/html-rewrite.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/flying-scripts/tags/1.2.4/lib/dom-parser.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/changeset | [email protected] | plugins.trac.wordpress.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Santh (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-10-09T18:22:21.000Z | Vendor Notified |
| CNA | 2026-10-15T15:35:09.000Z | Disclosed |
There are currently no legacy QID mappings associated with this CVE.