FalehSec Exploited-vulnerability triage · joined from CISA KEV, NVD CVSS and EPSS

CVE-2026-34909

Ubiquiti · UniFi OS · Ubiquiti UniFi OS Path Traversal Vulnerability

Verdict
Patch soon · actively exploited, reachable from the internet without credentials, and in the top 25% of CVEs by near-term exploitation probability

Added to CISA KEV 2026-06-23 · exploited in the wild for 96 days

What an attacker can reach How likely Time What CISA says to do Sources All 545

What an attacker can reach

CVSS 10.0 CRITICAL. The score is a summary; these three components are the part that decides whether something scanning the internet can use it.

Attack vectornetworkreachable over the network, with no local access needed
Privileges requirednoneneeds no credentials at all
User interactionnonecan be triggered with nobody interacting with the page or request
Base vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
WeaknessCWE-22

This describes the vulnerability. It says nothing about whether your systems run it.

How likely

EPSS puts the probability of exploitation in the next 30 days at 0.0179, which places it in the top 25% of all tracked CVEs. The percentile is the more useful half: 0.18 in absolute terms sounds low until you know most of the internet-facing software in the world scores under that.

EPSS probability0.0179
Percentile0.775 — top 25%

Time

Added to KEV2026-06-23
Days exploited96
Federal remediation duenot set
Ransomware useno known ransomware campaign use

What CISA says to do

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

A malicious actor with access to the network could exploit a Path Traversal vulnerability found in UniFi OS devices to access files on the underlying system that could be manipulated to access an underlying account.

Sources