Critical severity · published May 22, 2026
CVE-2026-34910
Ubiquiti UniFi OS Improper Input Validation Vulnerability
In wildKEV
10.0
CVSS
90%
EPSS
Yes
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)90.0% · higher than 100% of CVEs
Exploited in the wildYes
CISA KEVListed Jun 23, 2026
Federal remediation dueJun 26, 2026
Ransomware campaign useNot known
Affected products
Which versions
EF
EFG · Ubiquiti Inc
before 5.1.12 · source: vendor
EN
ENVR · Ubiquiti Inc
before 5.1.12 · source: vendor
EN
ENVR-Core · Ubiquiti Inc
before 5.1.12 · source: vendor
E7
Express 7 · Ubiquiti Inc
before 5.1.12 · source: vendor
UC
UCG-Fiber · Ubiquiti Inc
before 5.1.12 · source: vendor
UC
UCG-Industrial · Ubiquiti Inc
before 5.1.12 · source: vendor
UC
UCG-Max · Ubiquiti Inc
before 5.1.12 · source: vendor
UC
UCG-Ultra · Ubiquiti Inc
before 5.1.12 · source: vendor
UC
UCK · Ubiquiti Inc
before 5.1.12 · source: vendor
UC
UCK-Enterprise · Ubiquiti Inc
before 5.1.12 · source: vendor
UC
UCKP · Ubiquiti Inc
before 5.1.12 · source: vendor
UD
UDM · Ubiquiti Inc
before 5.1.12 · source: vendor
In the news
AdvisoryHigh
CISA Adds Four Known Exploited Vulnerabilities to Catalog
CISA has added four new vulnerabilities to its Known Exploited Vulnerabilities (KEV) Catalog , based on evidence of active exploitation.
CVE-2025-67038 Lantronix EDS5000 Code Injection Vulnerability
CVE-2026-34908 Ubiquiti UniFi OS Improper Access Control Vulnerability
CVE-2026-34909 Ubiquiti UniFi OS Path Traversal Vulnerability
CVE-2026-34910 Ubiquiti UniFi OS Improper Input Validation Vulnerability
These types of vulnerabilities are frequent attack vectors for malicious cyber actors and pose significant risks to the federal enterprise.
Binding Operational Directive (BOD) 26-04: Prioritizing Security Updates Based on Risk establishes vulnerability management requirements for Federal Civilian Executive Branch (FCEB) agencies. BOD 26-04 reinforces the importance of the KEV Catalog and requires federal agencies to prioritize rapid remediation of high-risk vulnerabilities, specifically those identified by Common Vulnerabilities and Exposures (CVEs) listed in CISA’s KEV Catalog on publicly exposed assets that grant total control of the asset post-exploitation, while deferring action for lower-risk vulnerabilities. BOD 26-04 further establishes basic expectations for when agencies must check whether threat actors compromised the system before the patch was applied.
While BOD 26-04 applies only to FCEB agencies, CISA encourages all organizations to adopt risk-based vulnerability management and prioritize remediation of KEV Catalog vulnerabiliti...
Jun 23, 2026·CISA Advisories
VulnerabilityHigh
[CISA KEV] CVE-2026-34910: Ubiquiti UniFi OS - Ubiquiti UniFi OS Improper Input Validation Vulnerability
Ubiquiti UniFi OS contains an improper input validation vulnerability which could allow a malicious actor with access to the network to conduct command injection.
UOUniFi OSCVE-2026-34910
Jun 23, 2026·CISA KEV
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-34910
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-34910
CISA KEV catalogue
https://www.cisa.gov/known-exploited-vulnerabilities-catalog
community.ui.com
https://community.ui.com/releases/Security-Advisory-Bulletin-064-064/84811c09-4cf4-42ab-bd61-cc994445963b
More from EFG
10.0
CVE-2026-34908
Ubiquiti UniFi OS Improper Access Control Vulnerability
10.0
CVE-2026-34909
Ubiquiti UniFi OS Path Traversal Vulnerability
9.9
CVE-2026-47370
A malicious actor with access to the network and low privileges could exploit an Improper Input Validation vulnerability found in certain devices running UniFi OS to execute a…
9.9
CVE-2026-47369
A malicious actor with access to the network and low privileges could exploit an Improper Input Validation vulnerability found in certain devices running UniFi OS to escalate…
8.6
CVE-2026-47368
A malicious actor with access to the network could exploit a Path Traversal vulnerability found in certain devices running UniFi OS to obtain data from such UniFi OS devices or…
