CVE-2026-66599 WordPress WPComplete plugin <= 2.9.5.6 - Cross Site Scripting (XSS) vulnerability
Unauthenticated attackers can inject malicious scripts into the WPComplete WordPress plugin, potentially leading to session hijacking or code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-66599?
CVE-2026-66599 is a high-severity cross-site scripting vulnerability in Liquid Web / StellarWP WPComplete, published on 24 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Unauthenticated Cross Site Scripting (XSS) in WPComplete <= 2.9.5.6 versions.
Weakness: CWE-79
Which versions are affected by CVE-2026-66599?
How do I fix CVE-2026-66599?
No fix has been published for CVE-2026-66599 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-66599 being exploited?
There is no known exploitation of CVE-2026-66599 in the wild and no public exploit code.
Sources
Also known as GHSA-phx4-j4pm-h7pj.