Out-of-bounds write in FortiOS - CVE-2025-53844
Published: May 12, 2026
Vulnerability identifier: #VU131196
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2025-53844
CWE-ID: CWE-787
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Fortinet, Inc
Affected software:
FortiOS
FortiOS
Detailed vulnerability description
The vulnerability allows a remote user to execute unauthorized code or commands.
The vulnerability exists due to out-of-bounds write in the CAPWAP daemon when handling CAPWAP communications from an authenticated FortiAP, FortiExtender, or FortiSwitch. A remote user can send crafted CAPWAP traffic to execute unauthorized code or commands.
Exploitation requires control of an authenticated FortiAP, FortiExtender, or FortiSwitch connected to the FortiGate device.
How to mitigate CVE-2025-53844
Install security update from vendor's website.