ACTIVELY EXPLOITED
CVE-2023-27997: Fortinet FortiOS and FortiProxy SSL-VPN Heap-Based Buffer Overflow Vulnerability
| Vendor | Fortinet |
|---|---|
| Product | FortiOS and FortiProxy SSL-VPN |
| Actively exploited | Yes |
| Added to CISA KEV | 13 Jun 2023 |
| CISA federal deadline | 4 Jul 2023 |
| Ransomware use | Known |
| Weakness (CWE) | CWE-122 |
Required action (CISA's text)
Apply updates per vendor instructions.
Description (NVD)
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.
SOURCES
Other Fortinet flaws
- CVE-2025-61624: Fortinet Multiple Products Path Traversal Vulnerability
- CVE-2026-104286: Fortinet FortiMail Path Traversal Vulnerability
- CVE-2025-25249: Fortinet Multiple Products Heap-based Buffer Overflow Vulnerability
- CVE-2025-68686: Fortinet FortiOS Exposure of Sensitive Information to an Unauthorized Actor Vulnerability
- CVE-2026-39808: Fortinet FortiSandbox OS Command Injection Vulnerability
Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.