# CVE-2026-54402 — Ubiquiti Inc UniFi OS Server

> As of 2026-07-02, CVE-2026-54402 is a CRITICAL-severity vulnerability in Ubiquiti Inc UniFi OS Server, CVSS v3.1 9.9, EPSS 1.7% (77.3th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-54402, most recently “CVE-2026-50746: Critical Unauthenticated Command Injection in Ubiquiti UniFi Connect Application (CVSS 10.0)”.

**Last updated:** 2026-07-02

## What is CVE-2026-54402?

A malicious actor with access to the network and low privileges could exploit an Improper Input Validation vulnerability found in UniFi OS to execute a Command Injection on the host device.

The record classifies CVE-2026-54402 under weakness class [CWE-20](https://intel.threadlinqs.com/cwe/CWE-20). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 12 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 118 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 9.9 — CRITICAL (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **EPSS (FIRST):** 1.7% probability of exploitation in the next 30 days, higher than 77.3% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-02

## Is CVE-2026-54402 being exploited?

It currently carries a trending score of 29 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [Ubiquiti Inc](https://intel.threadlinqs.com/vendors/ubiquiti): UniFi OS Server, Dream Machines, Enterprise Fortress Gateway, Dream Wall, Dream Routers, Express 7, Cloud Keys, Network Video Recorders, Enterprise Video Recorders, Cloud Gateways, Network Attached Storage, Enterprise Firewall Core

## How to fix CVE-2026-54402

No vendor patch reference has been recorded for CVE-2026-54402 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-2026-54402

1 tracked threat in the Threadlinqs corpus references CVE-2026-54402, either in the campaign’s CVE list or as an indicator on the campaign record.

- [CVE-2026-50746: Critical Unauthenticated Command Injection in Ubiquiti UniFi Connect Application (CVSS 10.0)](https://intel.threadlinqs.com/threat/TL-2026-1159) — CRITICAL · 2026-07-10

## Sources

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

**Other references**

- [community.ui.com](https://community.ui.com/releases/Security-Advisory-Bulletin-066-066/984eceb3-49c8-4227-942d-671c289b3afc)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-54402
Full detection coverage and IOCs for threats exploiting CVE-2026-54402 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp