ACTIVELY EXPLOITED
CVE-2019-5591: Fortinet FortiOS Default Configuration Vulnerability
| Vendor | Fortinet |
|---|---|
| Product | FortiOS |
| Actively exploited | Yes |
| Added to CISA KEV | 3 Nov 2021 |
| CISA federal deadline | 3 May 2022 |
| Ransomware use | Known |
| Weakness (CWE) | CWE-306 |
Required action (CISA's text)
Apply updates per vendor instructions.
Description (NVD)
Fortinet FortiOS contains a default configuration vulnerability that may allow an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the Lightweight Directory Access Protocol (LDAP) server.
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.