CVE-2026-34909

Ubiquiti UniFi OS Path Traversal Vulnerability

  • Critical 10.0
  • Exploited: added to CISA KEV 23 Jun 2026

Description

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.

Key facts

Published
22 May 2026
Last changed
24 Jun 2026
Assigned by
hackerone
KEV added
23 Jun 2026
KEV fix due
26 Jun 2026
EPSS
69.235% likely to be exploited in the next 30 days, higher than 99.367% of CVEs (scores for 15 Nov 2026)
SSVC (CISA)
Exploitation: active; Automatable: yes; Technical impact: total

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

  • 10.0CVSS 3.1, Criticalfrom the CNA (hackerone)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

What 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.CISA KEV required action

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

VendorProductVersions
Ubiquiti IncUniFi OS Server
  • Default status: unaffected
  • 0 up to but excluding 5.0.8 (affected)
Ubiquiti IncExpress
  • Default status: unaffected
  • 0 up to but excluding 4.0.14 (affected)
Ubiquiti IncUDM
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUDM-Pro
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUDM-SE
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUDM-Pro-Max
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUDM-Beast
  • Default status: unaffected
  • 0 up to but excluding 5.1.11 (affected)
Ubiquiti IncEFG
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUDW
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUDR
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUDR7
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUDR-5G
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncExpress 7
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUNVR
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUNVR-Pro
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUNVR-Instant
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUNVR-G2
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUNVR-G2-Pro
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncENVR
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncENVR-Core
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUNAS-2
  • Default status: unaffected
  • 0 up to but excluding 5.1.10 (affected)
Ubiquiti IncUNAS-4
  • Default status: unaffected
  • 0 up to but excluding 5.1.10 (affected)
Ubiquiti IncUNAS-Pro
  • Default status: unaffected
  • 0 up to but excluding 5.1.10 (affected)
Ubiquiti IncUNAS-Pro-4
  • Default status: unaffected
  • 0 up to but excluding 5.1.10 (affected)
Ubiquiti IncUNAS-Pro-8
  • Default status: unaffected
  • 0 up to but excluding 5.1.10 (affected)
Ubiquiti IncUCKP
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUCK
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUCK-Enterprise
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUCG-Ultra
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUCG-Max
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUCG-Fiber
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)
Ubiquiti IncUCG-Industrial
  • Default status: unaffected
  • 0 up to but excluding 5.1.12 (affected)

Timeline

  1. 22 May 2026 Published
  2. 23 Jun 2026 CVE-2026-34909 added to CISA KEV
  3. 23 Jun 2026 Added to the CISA KEV catalogue

Weakness

Practice this bug class

HackZoneLabs has a hands-on lab on Path traversal (CWE-22).

References