VulnerabilityDeferred

CVE-2026-109990

HIGH 7.2EPSS 0.33%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.33%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1: 7.2 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
EPSS: 0.33% probability · 26th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-79
Source: security@wordfence.com

EPSS trend

EPSS moved from 0.3% on 16 October 2026 to 0.3% on 26 October 2026.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.