CVE-2026-126258 Memory corruption in FortiOS
Unauthenticated attackers with wad port access can crash FortiOS proxy or ZTNA sessions via crafted HTTP requests.
- 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-2026-126258?
CVE-2026-126258 is a high-severity memory corruption vulnerability in Fortinet FortiOS, 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 stack-based buffer overflow vulnerability in Fortinet FortiOS 8.0.0, FortiOS 7.6.7 may allow an unauthenticated attacker with wad port access to crash proxy or ZTNA sessions via crafted HTTP or HTTPS requests.
Weakness: CWE-121
Which versions are affected by CVE-2026-126258?
An affected version is exposed as installed. No special setting or call is needed.
How do I fix CVE-2026-126258?
No fix has been published for CVE-2026-126258 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-2026-126258 being exploited?
There is no known exploitation of CVE-2026-126258 in the wild and no public exploit code.
Sources
Also known as GHSA-jx7c-cqh8-2v65.