# CVE-2026-25089 — Fortinet FortiSandbox

**CISA KEV**

> As of 2026-07-17, CVE-2026-25089 is a CRITICAL-severity vulnerability in Fortinet FortiSandbox, CVSS v3.1 9.1, EPSS 76.1% (99.5th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-07-16), with a US federal remediation deadline of 2026-07-19. Threadlinqs Intelligence links 6 tracked threat campaigns to CVE-2026-25089, most recently “Critical FortiSandbox GUI Authentication Bypass (CVE-2026-107656)”.

**Last updated:** 2026-07-17

## What is CVE-2026-25089?

A improper neutralization of special elements used in an os command ('os command injection') vulnerability in Fortinet FortiSandbox 5.0.0 through 5.0.5, FortiSandbox 4.4.0 through 4.4.8, FortiSandbox 4.2 all versions, FortiSandbox Cloud 5.0.4 through 5.0.5, FortiSandbox PaaS 5.0.4 through 5.0.5 may allow an unauthenticated attacker to execute unauthorized commands via specifically crafted HTTP requests

The record classifies CVE-2026-25089 under weakness class [CWE-78](https://intel.threadlinqs.com/cwe/CWE-78). Its CVSS v3 base vector states that the flaw is reachable remotely over the 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 127 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 9.1 — CRITICAL (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C`)
- **EPSS (FIRST):** 76.1% probability of exploitation in the next 30 days, higher than 99.5% of all scored CVEs
- **CISA KEV:** Listed since 2026-07-16, federal remediation deadline 2026-07-19
- **Threadlinqs priority:** 9/10 — CISA KEV-listed, which Threadlinqs floors at 9
- **Published:** 2026-06-09, last modified 2026-07-17

## Is CVE-2026-25089 being exploited?

CISA added CVE-2026-25089 to the Known Exploited Vulnerabilities catalog on 2026-07-16, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2026-07-19 under BOD 22-01. Weaponised exploit code for CVE-2026-25089 is publicly available. 2 public proof-of-concept repositories are tracked for this identifier. It currently carries a trending score of 58 in the Threadlinqs vulnerability feed.

- [HORKimhab/CVE-2026-25089](https://github.com/HORKimhab/CVE-2026-25089) (github)
- [0xBlackash/CVE-2026-25089](https://github.com/0xBlackash/CVE-2026-25089) (github)

## Affected products and versions

- [Fortinet](https://intel.threadlinqs.com/vendors/fortinet): FortiSandbox, FortiSandbox Cloud, FortiSandbox PaaS

## How to fix CVE-2026-25089

Because CVE-2026-25089 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2026-07-19. No vendor patch reference has been recorded for CVE-2026-25089 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-2026-25089

6 tracked threats in the Threadlinqs corpus reference CVE-2026-25089, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Critical FortiSandbox GUI Authentication Bypass (CVE-2026-107656)](https://intel.threadlinqs.com/threat/TL-2026-3433) — CRITICAL · 2026-10-13
- [CISA KEV: Fortinet FortiSandbox OS Command Injection Vulnerabilities Exploited (CVE-2026-39808, CVE-2026-25089)](https://intel.threadlinqs.com/threat/TL-2026-1432) — CRITICAL · 2026-07-17
- [CISA Orders Federal Agencies to Patch Exploited Fortinet FortiSandbox Command Injection Flaws (CVE-2026-39808, CVE-2026-25089, CVE-2026-39813)](https://intel.threadlinqs.com/threat/TL-2026-1433) — CRITICAL · 2026-07-17
- [CISA Orders Patch of Actively Exploited Critical FortiSandbox OS Command Injection Flaws (CVE-2026-39808, CVE-2026-25089, CVE-2026-39813)](https://intel.threadlinqs.com/threat/TL-2026-1447) — CRITICAL · 2026-07-17
- [FortiSandbox VNC Server Exposure Allows Unauthenticated Access to Scanning VMs (CVE-2026-59835)](https://intel.threadlinqs.com/threat/TL-2026-1319) — HIGH · 2026-07-14
- [FortiSandbox Unauthenticated RCE Chain: JRPC API Path-Traversal Auth Bypass and OS Command Injection (CVE-2026-39813, CVE-2026-39808, CVE-2026-25089)](https://intel.threadlinqs.com/threat/TL-2026-0823) — CRITICAL · 2026-06-16

## Sources

Enriched from CVE.org, FIRST EPSS, CISA KEV, GitHub Security Advisories, public proof-of-concept repositories. Last verified by Threadlinqs on 2026-10-10.

**Other references**

- [fortiguard.fortinet.com](https://fortiguard.fortinet.com/psirt/FG-IR-26-141)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-25089
Full detection coverage and IOCs for threats exploiting CVE-2026-25089 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp
