Ubiquiti UniFi OS Server path traversal

Summaryinfo

A vulnerability was found in Ubiquiti UniFi OS Server, UDM, UDM-Pro, UDM-SE, UDM-Pro-Max, UDM-Beast, EFG, UDW, UDR, UDR7, UDR-5G, Express 7, UNVR, UNVR-Pro, UNVR-Instant, UNVR-G2, UNVR-G2-Pro, ENVR, ENVR-Core, UNAS-2, UNAS-4, UNAS-Pro, UNAS-Pro-4, UNAS-Pro-8, UCKP, UCK, UCK-Enterprise, UCG-Ultra, UCG-Max, UCG-Fiber and UCG-Industrial. It has been declared as critical. Affected by this vulnerability is an unknown functionality. The manipulation results in path traversal. This vulnerability is reported as CVE-2026-34909. The attack can be launched remotely. Moreover, an exploit is present. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Ubiquiti UniFi OS Server, UDM, UDM-Pro, UDM-SE, UDM-Pro-Max, UDM-Beast, EFG, UDW, UDR, UDR7, UDR-5G, Express 7, UNVR, UNVR-Pro, UNVR-Instant, UNVR-G2, UNVR-G2-Pro, ENVR, ENVR-Core, UNAS-2, UNAS-4, UNAS-Pro, UNAS-Pro-4, UNAS-Pro-8, UCKP, UCK, UCK-Enterprise, UCG-Ultra, UCG-Max, UCG-Fiber and UCG-Industrial. Affected is some unknown processing. The manipulation with an unknown input leads to a path traversal vulnerability. CWE is classifying the issue as CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at community.ui.com. This vulnerability is traded as CVE-2026-34909 since 03/31/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details are unknown but an exploit is available. The MITRE ATT&CK project declares the attack technique as T1006.

It is declared as attacked. This issue was added on 06/23/2026 to the CISA Known Exploited Vulnerabilities Catalog with a due date of 06/26/2026:

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 BO

Upgrading eliminates this vulnerability. The upgrade is hosted for download at community.ui.com.

The vulnerability is also documented in the databases at EUVD (EUVD-2026-31384) and CERT Bund (WID-SEC-2026-1639). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Ubiquiti UniFi

Productinfo

Vendor

• Ubiquiti

Name

• EFG
• ENVR
• ENVR-Core
• Express 7
• UCG-Fiber
• UCG-Industrial
• UCG-Max
• UCG-Ultra
• UCK
• UCK-Enterprise
• UCKP
• UDM
• UDM-Beast
• UDM-Pro
• UDM-Pro-Max
• UDM-SE
• UDR
• UDR-5G
• UDR7
• UDW
• UNAS-2
• UNAS-4
• UNAS-Pro
• UNAS-Pro-4
• UNAS-Pro-8
• UniFi OS Server
• UNVR
• UNVR-G2
• UNVR-G2-Pro
• UNVR-Instant
• UNVR-Pro

License

• commercial

CPE 2.3info

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CPE 2.2info

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Threat Intelligenceinfo

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Sourcesinfo

Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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