CVE-2026-66640 WordPress Login With Ajax plugin <= 4.5.1 - Cross Site Scripting (XSS) vulnerability
A contributor can inject malicious scripts via the Login With Ajax plugin, potentially leading to code execution or account takeover.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-66640?
CVE-2026-66640 is a medium-severity cross-site scripting vulnerability in Marcus (aka @msykes) Login With Ajax, published on 18 Aug 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Contributor Cross Site Scripting (XSS) in Login With Ajax <= 4.5.1 versions.
Weakness: CWE-79
Which versions are affected by CVE-2026-66640?
How do I fix CVE-2026-66640?
No fix has been published for CVE-2026-66640 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-2026-66640 being exploited?
There is no known exploitation of CVE-2026-66640 in the wild and no public exploit code.
Sources
Also known as GHSA-cr8x-xwpq-5p62.