CVE-2026-34909: critical vulnerability in Ubiquiti Inc EFG
Published · Updated
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Prioritize patching. It under exploitation confirmed by CISA and has a public proof of concept.
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 network attacker can use a path traversal flaw in UniFi OS to access and modify system files, potentially gaining control of user accounts on the device.
Path traversal vulnerability (CWE-22) in UniFi OS allows an attacker with network access to bypass directory restrictions and read/write arbitrary system files; exploitation could lead to privilege escalation or account takeover by manipulating authentication-related files.
The full analysis of this CVE is available in Portuguese →
In the same product, most dangerous first.