Ubiquiti UniFi OS Path Traversal Vulnerability
Description
Ubiquiti UniFi OS contains a path traversal vulnerability which could allow a malicious actor with access to the network to access files on the underlying system that could be manipulated to access an underlying account.
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.
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Details
- Vendor
- Ubiquiti
- Product
- UniFi OS
- CVE
- CVE-2026-34909
- Affected versions
- UniFi OS Server 5.0: before 5.0.8 — fixed in 5.0.8
Express 4.0: before 4.0.14 — fixed in 4.0.14
UDM 5.1: before 5.1.12 — fixed in 5.1.12
UDM-Pro 5.1: before 5.1.12 — fixed in 5.1.12
UDM-SE 5.1: before 5.1.12 — fixed in 5.1.12
UDM-Pro-Max 5.1: before 5.1.12 — fixed in 5.1.12
UDM-Beast 5.1: before 5.1.11 — fixed in 5.1.11
EFG 5.1: before 5.1.12 — fixed in 5.1.12
UDW 5.1: before 5.1.12 — fixed in 5.1.12
UDR 5.1: before 5.1.12 — fixed in 5.1.12
UDR7 5.1: before 5.1.12 — fixed in 5.1.12
UDR-5G 5.1: before 5.1.12 — fixed in 5.1.12
Express 7 5.1: before 5.1.12 — fixed in 5.1.12
UNVR 5.1: before 5.1.12 — fixed in 5.1.12
UNVR-Pro 5.1: before 5.1.12 — fixed in 5.1.12
UNVR-Instant 5.1: before 5.1.12 — fixed in 5.1.12
UNVR-G2 5.1: before 5.1.12 — fixed in 5.1.12
UNVR-G2-Pro 5.1: before 5.1.12 — fixed in 5.1.12
ENVR 5.1: before 5.1.12 — fixed in 5.1.12
ENVR-Core 5.1: before 5.1.12 — fixed in 5.1.12
UNAS-2 5.1: before 5.1.10 — fixed in 5.1.10
UNAS-4 5.1: before 5.1.10 — fixed in 5.1.10
UNAS-Pro 5.1: before 5.1.10 — fixed in 5.1.10
UNAS-Pro-4 5.1: before 5.1.10 — fixed in 5.1.10
UNAS-Pro-8 5.1: before 5.1.10 — fixed in 5.1.10
UCKP 5.1: before 5.1.12 — fixed in 5.1.12
UCK 5.1: before 5.1.12 — fixed in 5.1.12
UCK-Enterprise 5.1: before 5.1.12 — fixed in 5.1.12
UCG-Ultra 5.1: before 5.1.12 — fixed in 5.1.12
UCG-Max 5.1: before 5.1.12 — fixed in 5.1.12 (from the advisory and NVD; check the exact builds in the official advisory) - CVSS score
- 10
- Actively exploited
- Yes, listed in the CISA Known Exploited Vulnerabilities catalog
- CISA due date
- June 26, 2026 (deadline for US federal agencies: a good benchmark for you too)
- Source
- CISA KEV – original advisory
- Published
- June 23, 2026
The description and the recommended action are quoted from the public advisory; severity, exploitation status and affected versions are compiled automatically from public sources and may contain errors. The vendor's original advisory prevails: check it before taking action. This information is provided without warranty and does not replace a professional assessment.