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CVE-2026-34909 KEVPublic exploit Critical · 10.0 EPSS 68.0%

Ubiquiti UniFi OS Path Traversal Vulnerability

Ubiquiti · UniFi OS

Summary

The flaw is a path traversal vulnerability in Ubiquiti's UniFi OS, the operating system used across its UniFi devices, which lets requests escape the intended directory and reach files elsewhere on the underlying system. An attacker with network access can exploit it without authentication or user interaction, reading or manipulating files on the system in ways that could be used to gain access to an underlying account.

Official description · NVD

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.

Breakdown
74.9 / 100
Exploited
Yes, in CISA KEV
Reports
0
Tactics
2/15

How an attack unfolds

Based on mappings. Select a step to see the evidence.
  1. How attackers get in

  2. What they do

First seen exploited 18 days after disclosure.

  1. Disclosedday 0
  2. First seen exploitedVulnCheck KEV evidence+18 days
  3. Added to CISA KEVEU database agrees+32 days

CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.

techniques

2 , grouped by in kill-chain order, 2 cited passages 2

Initial AccessTA0001

Exploit Public-Facing Application T1190 Medium
AI mapping from the description · how it is exploited

network-reachable path traversal exploit of appliance

A malicious actor with access to the network could exploit a Path Traversal vulnerability found in UniFi OS devices
From the official description (NVD) Original (opens in a new tab) ↗

CollectionTA0009

Data from Local System T1005 Medium
AI mapping from the description · primary impact

direct file access on underlying system

to access files on the underlying system
From the official description (NVD) Original (opens in a new tab) ↗

Detection

0 rules for this CVE · 163 general rules for its techniques

Rules for this CVE

0 that reference CVE-2026-34909 directly.

CVE-specific rules are not available in this build. Search SigmaHQ ↗

Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.

What security researchers reported

Not named in any threat report yet

Also mentioned in 50 community threat pulses (AlienVault OTX)

Weaker evidence

Pulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.

References

3 links, grouped by NVD tag
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