Vulnerabilities
CVE-2019-5591 — Fortinet FortiOS Default Configuration Vulnerability
CVE-2019-5591 · Fortinet FortiOS · CVSS 6.5 · KEV
In brief
- Severity · CVSS
- Medium6.5CVSS 3.1, Medium
- EPSS
- 18%
- CISA KEV
- Known exploited, listed since 3 Nov 2021
- CERT-FR
- No advisory or alert referenced in the catalog
- Vendor
- Fortinet
- Published · Modified
- ·
- Last verified
Summary
A Default Configuration vulnerability in FortiOS may allow an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the LDAP server.
Weakness: CWE-306
Title, description and the vendor's statements are quoted from the CVE record; a vendor's advisory is summarised in Patcharo's words, with a link.
Affected and fixed versions
Per product and release branch, as the vendor's CVE record and official advisory state them. A fixed release is shown only when a document names it: the vendor's, or CERT-FR's for Check Point, with its source.
No precise fixed release is published in the sources Patcharo follows.
Fortinet FortiOS
Source: CVE-2019-5591
- —Affected versionsFortiOS 6.2.0 and below.First fixed releaseNot published in the sources followed
No precise fixed release is published for this product in the sources Patcharo follows.
Remediation
Vendor guidance
Vendor advisory
The vendor has published an advisory for this CVE: check it for fixed releases and mitigations.
SourceFortiGuard FG-IR-19-037
Last verified 1 Oct 2026 at 09:30 UTC
Known exploitation
Added to CISA KEV on 3 Nov 2021
Federal remediation due date: 3 May 2022
Known use in ransomware campaigns
18% probability of exploitation in the next 30 days (percentile 97%).
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CERT-FR
No CERT-FR advisory or alert of the last two years references this CVE, for the vendors Patcharo covers.
Timeline
- Published by the source
- Added to CISA KEV
- CISA remediation due date
- Source record last modified
- EPSS score computed
- Last verified by Patcharo
Official sources
- Fortinet (CVE record)retrieved 1 Oct 2026 at 09:30 UTC
- CISA Known Exploited Vulnerabilitiesretrieved 1 Oct 2026 at 09:28 UTC
- NVDretrieved 27 Sept 2026 at 23:44 UTC
- FIRST EPSSretrieved 30 Sept 2026 at 00:17 UTC
- FortiGuard FG-IR-19-037retrieved 1 Oct 2026 at 09:30 UTC
Vendor advisory
Fortinet · CISA Known Exploited Vulnerabilities · NVD · FIRST EPSS · FortiGuard FG-IR-19-037
How Patcharo reads this
Affected and fixed releases come from the vendor's structured statements and are matched against exact versions; CVSS from NVD, exploitation from CISA KEV and the vendor's own advisory, probability from FIRST EPSS. Missing data stays Unknown and never becomes Not affected.
Read the methodologyRead the guide: FortiOS version numbering: branches, patch releases and the Feature and Mature labels