Stored XSS in WordPress Web Vitals Tracking Plugin

The Web Vitals Tracking WordPress plugin through 5.4.2 does not validate or escape performance measurements submitted by unauthenticated visitors before storing them and outputting them in a script context on an administrative page, allowing unauthenticated attackers to perform Stored Cross-Site Scripting attacks against administrators.

Casky was already ahead

This CVE exploits attack patterns that Casky's 323matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

The Web Vitals Tracking WordPress plugin through version 5.4.2 contains a Stored Cross-Site Scripting (CWE-79) vulnerability that allows unauthenticated attackers to inject malicious scripts into performance measurement data. Because the plugin fails to validate or escape user-submitted performance metrics before storing them in the database and later outputting them in administrative pages, attackers can craft payloads that execute in the browsers of WordPress administrators. This is particularly dangerous because it requires no authentication, affects all installations of the vulnerable plugin versions, and targets high-privilege users who have access to sensitive site configuration and user data.

Casky's 323 mapped skills leverage Claude's extended reasoning to detect the attack patterns behind this vulnerability across MITRE ATT&CK techniques TA0001 (Initial Access) and TA0043 (Reconnaissance). Practitioners using Casky would identify anomalies in several ways: detecting unvalidated input flows where external performance data enters database storage without sanitization (CWE-79 pattern), identifying script context output on administrative pages that renders unsanitized data, and spotting the reconnaissance phase where attackers probe the plugin's endpoints to understand acceptable input formats. The platform's skill correlation would reveal how an attacker moves from initial reconnaissance of the vulnerable parameter through exploitation to payload delivery against administrators, helping security teams prioritize remediation and implement input validation and output encoding controls across their WordPress infrastructure.

Live Threat IntelligenceComing soon

Casky Risk Score

—

EPSS Probability

—

Shodan Exposure

—

GreyNoise Signal

—

Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

323 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-87760.

Abuse of Public-Facing API: Mobile API Abuse

mobile security · low

Run

abusing-dpapi-for-credential-access

red teaming · high

Run

abusing-shadow-credentials-for-privesc

red teaming · high

Run

MITRE ATT&CK Techniques

TA0001 TA0043

Investigate the attack patterns behind CVE-2026-87760

Casky has 323 skills that investigate the attack patterns behind CVE-2026-87760. Run one and get CVSS-scored findings in 3 minutes.

Run the skill that detects this →

X Instagram LinkedIn