CVE-2019-5591
Fortinet FortiOS Default Configuration Vulnerability
- Medium 6.5
- Exploited: added to CISA KEV 3 Nov 2021
- Used in ransomware campaigns
Description
A Default Configuration vulnerability in FortiOS may allow an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the LDAP server.
Key facts
- Published
- 14 Aug 2020
- Last changed
- 15 Aug 2026
- Assigned by
- fortinet
- KEV added
- 3 Nov 2021
- KEV fix due
- 3 May 2022
- Used in ransomware
- Yes, according to CISA
- EPSS
- 18.566% likely to be exploited in the next 30 days, higher than 97.302% of CVEs (scores for 15 Nov 2026)
- SSVC (CISA)
- Exploitation: active; Automatable: no; Technical impact: partial
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 6.5CVSS 3.1, Mediumfrom CISA (ADP container)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
What to do
- Apply updates per vendor instructions.CISA KEV required action
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| Fortinet | Fortinet FortiOS |
|
Timeline
- 14 Aug 2020 Published
- 3 Nov 2021 CVE-2019-5591 added to CISA KEV
- 3 Nov 2021 Added to the CISA KEV catalogue