CVE-2026-66599

WordPress WPComplete plugin <= 2.9.5.6 - Cross Site Scripting (XSS) vulnerability

Published Aug 24, 2026 CVSS 3.1 · 7.1 High EPSS < 1% KEV · Not listed
Description
Unauthenticated Cross Site Scripting (XSS) in WPComplete <= 2.9.5.6 versions.

Analysis

AI-generated

Technical impact

The vulnerability described allows an attacker to inject arbitrary client‑side script into pages served by the WordPress WPComplete plugin. Because the plugin does not properly escape or validate input, any user able to access the plugin’s functionality can create requests that result in scripts being rendered in the victim’s browser. The weakness is identified as an XSS flaw (CWE‑79).

Affected Systems

WordPress sites that have the WPComplete plugin version 2.9.5.6 or earlier from Liquid Web / StellarWP are affected. No other versions or unrelated WordPress plugins are listed as impacted. Updates to 2.9.5.7 or later address the issue.

Risk and Exploitability

The CVSS score of 7.1 indicates a moderate to high severity. The EPSS score is not available, so the likelihood of exploitation cannot be estimated from public data. The vulnerability is not listed in CISA's KEV catalog, suggesting no publicly known exploited cases at the time of reporting. According to the description, the flaw is unauthenticated, meaning an attacker can craft requests without needing to log in. The attack likely involves sending malicious input to the plugin’s endpoints, making it a remote, low‑barrier vector.

Remediation

Vendor Solution

Update the WordPress WPComplete Plugin to the latest available version (at least 2.9.5.7).


OpenCVE Recommended Actions

  • Update the WPComplete plugin to version 2.9.5.7 or newer.
  • If the plugin is not required, temporarily disable or uninstall it to remove the attack surface.
  • Implement a site‑wide Content Security Policy that disallows inline script execution to mitigate any residual XSS payloads.

Generated by OpenCVE AI on August 24, 2026 at 12:53 UTC.

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Liquid Web / Stellarwp
Liquid Web / Stellarwp wpcomplete
Wordpress
Wordpress wordpress
Vendors & Products Liquid Web / Stellarwp
Liquid Web / Stellarwp wpcomplete
Wordpress
Wordpress wordpress
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Unauthenticated Cross Site Scripting (XSS) in WPComplete <= 2.9.5.6 versions.
Title WordPress WPComplete plugin <= 2.9.5.6 - Cross Site Scripting (XSS) vulnerability
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L'}

Weaknesses
  • CWE-79

    Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Sources

Status
PUBLISHED
Assigner
Patchstack
Published
Updated
Aug 24, 2026, 1:01 PM
Reserved
Jul 27, 2026, 2:00 PM
Status
Deferred
Published
Aug 24, 2026, 12:16 PM
Modified
Oct 12, 2026, 3:10 PM