# CVE-2024-55599 — Fortinet FortiOS

> As of 2026-08-11, CVE-2024-55599 is a MEDIUM-severity vulnerability in Fortinet FortiOS, CVSS v3.1 4.9, EPSS 0.3% (32.1th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2024-55599, most recently “Multiple Vulnerabilities in Fortigate NGFW on RUGGEDCOM APE1808 Devices (SSA-864900) — Including Actively Exploited FortiCloud SSO Bypass (CVE-2025-59718/-59719) and FortiOS Heap Overflow (CVE-2025-25249)”.

**Last updated:** 2026-08-11

## What is CVE-2024-55599?

An Improperly Implemented Security Check for Standard vulnerability [CWE-358] in FortiOS version 7.6.0, version 7.4.7 and below, 7.0 all versions, 6.4 all versions and FortiProxy version 7.6.1 and below, version 7.4.8 and below, 7.2 all versions, 7.0 all versions may allow a remote unauthenticated user to bypass the DNS filter via Apple devices.

The record classifies CVE-2024-55599 under weakness class [CWE-358](https://intel.threadlinqs.com/cwe/CWE-358). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 473 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 4.9 — MEDIUM (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:U/RL:X/RC:X`)
- **EPSS (FIRST):** 0.3% probability of exploitation in the next 30 days, higher than 32.1% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 3.7/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2025-07-08, last modified 2026-08-11

## Is CVE-2024-55599 being exploited?

It currently carries a trending score of 13 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [Fortinet](https://intel.threadlinqs.com/vendors/fortinet): FortiOS, FortiProxy

## How to fix CVE-2024-55599

No vendor patch reference has been recorded for CVE-2024-55599 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2024-55599

1 tracked threat in the Threadlinqs corpus references CVE-2024-55599, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Multiple Vulnerabilities in Fortigate NGFW on RUGGEDCOM APE1808 Devices (SSA-864900) — Including Actively Exploited FortiCloud SSO Bypass (CVE-2025-59718/-59719) and FortiOS Heap Overflow (CVE-2025-25249)](https://intel.threadlinqs.com/threat/TL-2026-2486) — CRITICAL · 2026-09-13

## Sources

Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-10-10.

**Other references**

- [fortiguard.fortinet.com](https://fortiguard.fortinet.com/psirt/FG-IR-24-053)

Canonical: https://intel.threadlinqs.com/cve/CVE-2024-55599
Full detection coverage and IOCs for threats exploiting CVE-2024-55599 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp