# CVE-2025-25253 — Fortinet FortiProxy

> As of 2026-08-11, CVE-2025-25253 is a MEDIUM-severity vulnerability in Fortinet FortiProxy, CVSS v3.1 6.8, EPSS 0.1% (1.3th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2025-25253, 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-2025-25253?

An Improper Validation of Certificate with Host Mismatch vulnerability [CWE-297] in FortiProxy version 7.6.1 and below, version 7.4.8 and below, 7.2 all versions, 7.0 all versions and FortiOS version 7.6.2 and below, version 7.4.8 and below, 7.2 all versions, 7.0 all versions ZTNA proxy may allow an unauthenticated attacker in a man-in-the middle position to intercept and tamper with connections to the ZTNA proxy

The record classifies CVE-2025-25253 under weakness class [CWE-297](https://intel.threadlinqs.com/cwe/CWE-297). Its CVSS v3 base vector states that the flaw is reachable from an adjacent network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 3 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 361 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 6.8 — MEDIUM (`CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R`)
- **EPSS (FIRST):** 0.1% probability of exploitation in the next 30 days, higher than 1.3% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 3.5/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2025-10-14, last modified 2026-08-11

## Is CVE-2025-25253 being exploited?

It currently carries a trending score of 5 in the Threadlinqs vulnerability feed.

## Affected products and versions

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

## How to fix CVE-2025-25253

No vendor patch reference has been recorded for CVE-2025-25253 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-2025-25253

1 tracked threat in the Threadlinqs corpus references CVE-2025-25253, 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-24-457)

Canonical: https://intel.threadlinqs.com/cve/CVE-2025-25253
Full detection coverage and IOCs for threats exploiting CVE-2025-25253 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp