Actively Exploited, CISA KEV

CVE-2026-34910: Ubiquiti UniFi OS Critical Vulnerability

Severity: Critical | CVSS 3.1: 10.0 | Published: 2026-05-22 | KEV Added: 2026-06-23

What is 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.

Technical Analysis

Weakness Classification

This vulnerability is classified as CWE-20, Improper Input Validation. The software does not properly validate input, allowing attackers to craft inputs that cause unexpected behavior, data corruption, or code execution.

Attack Vector Breakdown

  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Changed
  • Confidentiality: High
  • Integrity: High
  • Availability: High

Impact Analysis

This vulnerability is exploitable over the network, meaning any system reachable via the internet or internal network is potentially at risk without physical access. The attack complexity is low, requires no special privileges, and needs no user interaction, making it straightforward to exploit at scale. Successful exploitation can result in full confidentiality breach (complete data disclosure), complete integrity compromise (data modification or code execution), total availability loss (denial of service). Notably, the vulnerability's scope is changed, meaning exploitation can affect resources beyond the vulnerable component, for example, escaping a sandbox or container to impact the host system. The software does not properly validate input, allowing attackers to craft inputs that cause unexpected behavior, data corruption, or code execution.

Exploitation Probability (EPSS): 87.0% chance of exploitation in the next 30 days (100th percentile). This places the vulnerability in the highest risk tier, immediate action is critical.

Is CVE-2026-34910 being exploited?

Yes. CVE-2026-34910 is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, restricted to CVEs with confirmed active exploitation in the wild. CISA added this vulnerability on 2026-06-23. Inclusion in KEV triggers the patching mandate under BOD 22-01 for U.S. federal civilian agencies, with a remediation deadline of 2026-06-26.

How to fix CVE-2026-34910

Apply the security update issued by Ubiquiti for UniFi OS. If an immediate patch is not possible, consult the vendor advisory for mitigation guidance, restrict network exposure of the affected service, and monitor logs for indicators of exploitation. CISA's Known Exploited Vulnerabilities catalog requires U.S. federal agencies to remediate this vulnerability by the due date shown below under Binding Operational Directive 22-01. Private organizations should treat KEV entries as priority-one patches because active exploitation has been confirmed in the wild.

Related Vulnerabilities

Other actively exploited vulnerabilities affecting UniFi OS or sharing the same weakness (CWE-20):

  • CVE-2026-34909 (Critical 10.0) [same product], A malicious actor with access to the network could exploit a Path Traversal…
  • CVE-2026-34908 (Critical 10.0) [same product], A malicious actor with access to the network could exploit an Improper Access…
  • CVE-2026-12569 (Critical 9.8) [same CWE], A critical remote code execution (RCE) vulnerability has been reported in PTC…
  • CVE-2026-6973 (High 7.2) [same CWE], An Improper Input Validation in Ivanti EPMM before versions 12.6.1.1…
  • CVE-2026-34197 (High 8.8) [same CWE], Improper Input Validation, Improper Control of Generation of Code ('Code…

Frequently asked questions

Is CVE-2026-34910 critical?

CVE-2026-34910 has a CVSS 3.1 base score of 10.0, Critical severity. It should be treated as a priority patch, especially given the active exploitation confirmed by CISA.

Is CVE-2026-34910 being actively exploited?

Yes, CISA added CVE-2026-34910 to the Known Exploited Vulnerabilities catalog on 2026-06-23. Inclusion in KEV means CISA has confirmed in-the-wild exploitation.

How do I patch CVE-2026-34910?

Apply the security update from Ubiquiti for UniFi OS. Federal agencies must remediate by 2026-06-26 under BOD 22-01.

What type of vulnerability is CVE-2026-34910?

CVE-2026-34910 is classified under CWE-20 (Improper Input Validation). The software does not properly validate input, allowing attackers to craft inputs that cause unexpected behavior, data corruption, or code execution.

What is the CVSS score for CVE-2026-34910?

CVE-2026-34910 has a CVSS 3.1 base score of 10.0, classifying it as Critical severity. The attack vector is Network, attack complexity is Low, and no privileges are required.