Buffer over-read in FortiProxy and FortiOS - CVE-2026-59840
Published: July 14, 2026
Vulnerability identifier: #VU137531
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-59840
CWE-ID: CWE-126
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote authenticated user to gain access to sensitive information.
The vulnerability exists due to buffer over-read in authd and wad daemon. An authenticated remote attacker can return a portion of device memory in the redirect response via submitting a specially crafted request.
Affected software
FortiProxy
FortiOS
FortiOS
How to mitigate CVE-2026-59840
Install update from vendor's website.
FortiProxy - addressed in versions 7.4.14, 7.6.6
FortiOS - addressed in versions 7.4.9, 7.6.4
FortiOS - addressed in versions 7.4.9, 7.6.4