Warning: Ubiquiti has addressed multiple critical vulnerabilities in UniFi OS. Patch Immediately!

Veröffentlicht : 26/05/2026

Last Update: 26/05/2026

    * Affected products:
         → Ubiquiti Inc UniFi OS

    * Type: Improper Access Control, Path Traversal, Improper Input Validation

    * CVE/CVSS:

CVE-2026-34908: CVSS 10.0 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H)
CVE-2026-34909: CVSS 10.0 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H)
CVE-2026-34910: CVSS 10.0 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H)
CVE-2026-33000: CVSS 9.1 (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H)

Sources

UniFi - https://community.ui.com/releases/Security-Advisory-Bulletin-064-064/84811c09-4cf4-42ab-bd61-cc994445963b

Risks

Ubiquiti has released security updates to address multiple critical vulnerabilities in UniFi OS, designed for managing IT infrastructure including networking, security, and other services. The vulnerabilities could allow remote attackers to make unauthorized system changes, access sensitive files, disclose information, or execute arbitrary commands on vulnerable systems, highly impacting the confidentiality, integrity and availability of targeted devices.

Given that UniFi OS devices are often centrally integrated into networks, successful compromise could enable lateral movement and broader network compromise.

The security update addresses 4 critical vulnerabilities:

CVE-2026-34908: CVSS 10.0 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H)
CVE-2026-34909: CVSS 10.0 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H)
CVE-2026-34910: CVSS 10.0 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H)
CVE-2026-33000: CVSS 9.1 (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H)

Description

CVE-2026-34908: 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, potentially leading to full device compromise.

CVE-2026-34909: 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 and compromise an underlying account.

CVE-2026-34910: A malicious actor with access to the network could exploit an Improper Input Validation vulnerability found in UniFi OS devices to execute a Command Injection on the affected devices, potentially leading to arbitrary command execution.

CVE-2026-33000: A malicious actor with access to the network and high privileges could exploit an Improper Input Validation vulnerability found in UniFi OS devices to execute a Command Injection.

These vulnerabilities affect the following Ubiquiti UniFi OS products:

UCG-Industrial (Version 5.0.13 and earlier)
UDM, UDM-Pro, UDM-SE, UDM-Pro-Max, EFG, UDW, UDR, UDR7, Express 7, UNVR, UNVR-Pro, UNVR-Instant, ENVR, UCG-Ultra, UCG-Max and UCG-Fiber (Version 5.0.16 and earlier)
UDR-5G, ENVR-Core, UCKP, UCK and UCK-Enterprise (Version 5.0.17 and earlier)
UniFi OS Server (Version 5.0.6 and earlier)
UNVR-G2 and UNVR-G2-Pro (Version 5.1.11 and earlier)
UDM-Beast, UNAS-2, UNAS-4, UNAS-Pro, UNAS-Pro-4 and UNAS-Pro-8 (Version 5.1.8 and earlier)

Additionally, for CVE-2026-34909 only: Express running versions 4.0.13 and earlier;

Recommended Actions

Patch
The Centre for Cybersecurity Belgium strongly recommends installing updates for vulnerable devices with the highest priority after thorough testing.

Monitor/Detect
The CCB recommends organizations upscale monitoring and detection capabilities to identify any related suspicious activity, ensuring a swift response in case of an intrusion.

In case of an intrusion, you can report an incident via https://ccb.belgium.be/cert/report-incident.

While patching appliances or software to the newest version may provide safety from future exploitation, it does not remediate historic compromise.

References

NVD