Quantum Secular Labs / Blog / Advisories

CVE-2026-34908: Ubiquiti UniFi OS Improper Access Control Vulnerability

CVE-2026-34908 is rated critical with a CVSS v3.1 base score of 10.0 and affects Ubiquiti UniFi OS, along with 30 other products in NVD’s configuration data. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available. CISA added it to its Known Exploited Vulnerabilities catalog on 2026-06-23, which means exploitation in the wild has been observed.

Vulnerability description

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.

Severity breakdown

CVSS v3.1 10.0: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Changed. Impact reaches beyond the vulnerable component to other resources.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-284: Improper Access Control

The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

Affected products

  • Ui Unifi OS Server: before 5.0.8
  • Ui Unifi Cloud Gateway Industrial Firmware: before 5.1.12
  • Ui Unifi Dream Machine Firmware: before 5.1.12
  • Ui Unifi Dream Machine Pro Firmware: before 5.1.12
  • Ui Unifi Dream Machine Special Edition Firmware: before 5.1.12
  • Ui Unifi Dream Machine Pro Max Firmware: before 5.1.12
  • Ui Enterprise Fortress Gateway Firmware: before 5.1.12
  • Ui Unifi Dream Wall Firmware: before 5.1.12
  • Ui Unifi Dream Router Firmware: before 5.1.12
  • Ui Unifi Dream Router 7 Firmware: before 5.1.12
  • Ui Unifi Express 7 Firmware: before 5.1.12
  • Ui Unifi Network Video Recorder Firmware: before 5.1.12
  • Ui Unifi Network Video Recorder Pro Firmware: before 5.1.12
  • Ui Unifi Network Video Recorder Instant Firmware: before 5.1.12
  • Ui Enterprise Network Video Recorder Firmware: before 5.1.12

References