CVE-2026-126154 Memory corruption in FortiMail
Remote unauthenticated attackers can crash FortiMail with a crafted HTTP request triggering an out-of-bounds write.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Harmful if only installed
- No
- Needs a specific call
- No
- Fix
- None listed
What is CVE-2026-126154?
CVE-2026-126154 is a high-severity memory corruption vulnerability in Fortinet FortiMail, published on 11 Nov 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A out-of-bounds write vulnerability in Fortinet FortiMail 8.0.0 through 8.0.1, FortiMail 7.6.0 through 7.6.6, FortiMail 7.4.0 through 7.4.8, FortiMail 7.2 all versions may allow a remote unauthenticated attacker to cause a denial of service via a specially crafted HTTP request.
Weakness: CWE-787
Which versions are affected by CVE-2026-126154?
An affected version is exposed as installed. No special setting or call is needed.
How do I fix CVE-2026-126154?
No fix has been published for CVE-2026-126154 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-126154 being exploited?
There is no known exploitation of CVE-2026-126154 in the wild and no public exploit code.
Sources
Also known as GHSA-9cmj-x939-3vm5.