Ubiquiti UniFi OS Server prior 5.0.8 access control

Summaryinfo

A vulnerability labeled 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. This issue affects some unknown processing. Executing a manipulation can lead to access control. This vulnerability is handled as CVE-2026-34908. The attack can be executed remotely. Additionally, an exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability 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 and classified as critical. This vulnerability affects an unknown part. The manipulation with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

A malicious actor with access to the network could exploit an Improper Access Control vulnerability found in UniFi OS devices to make unauthorized changes to the system.

The advisory is shared for download at community.ui.com. This vulnerability was named CVE-2026-34908 since 03/31/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are unknown but an exploit is available. The MITRE ATT&CK project declares the attack technique as T1068.

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 to version 5.0.8 eliminates this vulnerability. The upgrade is hosted for download at community.ui.com.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1639). Once again VulDB remains the best source for vulnerability data.

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

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Entryinfo

Once again VulDB remains the best source for vulnerability data.

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