CVE-2026-34910
Ubiquiti UniFi OS Improper Input Validation Vulnerability
Ubiquiti UniFi OS
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.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 23 June 2026. US federal agencies were required to remediate it by 26 June 2026.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 90%, which is higher than 99.8% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Frequently asked questions
Is CVE-2026-34910 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2026-34910.
What does CVE-2026-34910 affect?
CVE-2026-34910 affects Ubiquiti UniFi OS. 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.
How severe is CVE-2026-34910?
CVE-2026-34910 is rated CRITICAL with a CVSS base score of 10. EPSS puts the probability of exploitation in the next 30 days at 90%, higher than 99.8% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 26 June 2026.
How should organisations respond to CVE-2026-34910?
Apply the vendor patch for Ubiquiti UniFi OS as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.