Fortinet FortiOS and FortiProxy SSL-VPN
YES - ON THE CISA KEV LIST
CVE-2023-27997
Fortinet FortiOS and FortiProxy SSL-VPN Heap-Based Buffer Overflow Vulnerability
overdue since 2023-07-04
Fortinet: 32 entries (1.8% of all KEV entries are from this vendor); 9 added in 2026.
BOD 26-04 note: this is the date printed in the CISA catalog. A federal agency's actual deadline is set by its SSVC tier - Act (3 days), Attend (14 days), Track (60 days), or the next scheduled upgrade - counted from the KEV listing date or the date the vulnerability is identified in its environment, whichever comes first. Use the tier helper on each CVE page for your own window.
Your BOD 26-04 window (SSVC tier helper)
Your remediation window ends:
Description
Fortinet FortiOS and FortiProxy SSL-VPN contain a heap-based buffer overflow vulnerability which can allow an unauthenticated, remote attacker to execute code or commands via specifically crafted requests.
Required action (CISA)
Apply updates per vendor instructions.
Notes
https://www.fortiguard.com/psirt/FG-IR-23-097; https://nvd.nist.gov/vuln/detail/CVE-2023-27997
References
Other KEV entries for this vendor: Fortinet
- CVE-2025-61624 - Multiple Products (2026-10-16)
- CVE-2026-104286 - FortiMail (2026-10-01)
- CVE-2025-25249 - Multiple Products (2026-09-09)
- CVE-2025-68686 - FortiOS (2026-07-27)
- CVE-2026-25089 - FortiSandbox (2026-07-16)
- CVE-2026-39808 - FortiSandbox (2026-07-16)
- CVE-2026-21643 - FortiClient EMS (2026-04-13)
- CVE-2026-35616 - FortiClient EMS (2026-04-06)
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