A malicious actor with access to the network could exploit an Improper Input Validation vulnerability found in UniFi OS devices to execute…

cisa required action 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 BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

1. 2026-05-22 CISA SSVC: exploitation active
2. 2026-05-22 Published
3. 2026-06-23 Added to CISA KEV
4. 2026-06-26 CISA patch deadline

Added

4 mo ago (2026-06-23)

Patch by

2026-06-26 (4 mo ago)

Ransomware

Not known

Required action

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 BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Vendor, product

Ubiquiti, UniFi OS

CISA name

Ubiquiti UniFi OS Improper Input Validation Vulnerability

Exploitation

Active, exploited in the wild

Automatable

yes

Technical impact

total

Assessed

5 mo ago (2026-05-22)

90.03% chance of exploitation in the next 30 days, higher than 99.7% of all scored CVEs (FIRST EPSS, 2026-11-08).

• Nuclei template UniFi OS Server - Command Injection nuclei detection template
• pwndefend.com https://www.pwndefend.com/2026/06/09/cve-2026-34910-exploitation-itw-building-a-botnet-mirai/ referenced PoC, tagged "exploit" by a source, unverified

• Ubiquiti Inc UniFi OS Server
• Ubiquiti Inc UDM
• Ubiquiti Inc UDM-Pro
• Ubiquiti Inc UDM-SE
• Ubiquiti Inc UDM-Pro-Max
• Ubiquiti Inc UDM-Beast
• Ubiquiti Inc EFG
• Ubiquiti Inc UDW
• Ubiquiti Inc UDR
• Ubiquiti Inc UDR7
• Ubiquiti Inc UDR-5G
• Ubiquiti Inc Express 7
• Ubiquiti Inc UNVR
• Ubiquiti Inc UNVR-Pro
• Ubiquiti Inc UNVR-Instant
• Ubiquiti Inc UNVR-G2
• Ubiquiti Inc UNVR-G2-Pro
• Ubiquiti Inc ENVR
• Ubiquiti Inc ENVR-Core
• Ubiquiti Inc UNAS-2
• Ubiquiti Inc UNAS-4
• Ubiquiti Inc UNAS-Pro
• Ubiquiti Inc UNAS-Pro-4
• Ubiquiti Inc UNAS-Pro-8
• Ubiquiti Inc UCKP
• Ubiquiti Inc UCK
• Ubiquiti Inc UCK-Enterprise
• Ubiquiti Inc UCG-Ultra
• Ubiquiti Inc UCG-Max
• Ubiquiti Inc UCG-Fiber
• Ubiquiti Inc UCG-Industrial

Weakness

• CWE-20 Improper Input Validation

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

  patch, vendor-advisory

• pwndefend.com /2026/06/09/cve-2026-34910-exploitation-itw-building-a-botnet-mirai/

  third-party-advisory, exploit

• cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-34910

  government-resource, us-government-resource

• CVE List CVE-2026-34910
• NVD CVE-2026-34910

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.