CVE-2026-66358 Cross-site scripting in acmailer CGI
An attacker can execute arbitrary scripts via a cross-site scripting vulnerability in acmailer, potentially compromising user sessions.
- 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-2026-66358?
CVE-2026-66358 is a medium-severity cross-site scripting vulnerability in Extra Innovation Inc. acmailer CGI, published on 19 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
A cross-site scripting vulnerability exists in acmailer, which may allow an attacker to execute an arbitrary script.
Weakness: CWE-79
Which versions are affected by CVE-2026-66358?
How do I fix CVE-2026-66358?
No fix has been published for CVE-2026-66358 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-2026-66358 being exploited?
There is no known exploitation of CVE-2026-66358 in the wild and no public exploit code.
Sources
Also known as GHSA-qv73-xfjm-gc7w.