CVE-2026-21639: Command Injection

Published Jan 8, 2026
·
Updated

A malicious actor in Wi-Fi range of the affected product could leverage a vulnerability in the airMAX Wireless Protocol to achieve a remote code execution (RCE) within the affected product.

Affected Software

12 affected components
Ubiquiti airMAX AC<=8.7.20
Ubiquiti airMAX M<=6.3.22
Ubiquiti airFiber AF60-XG<=1.2.2
Ubiquiti airFiber AF60<=2.6.7
All of the following
UI Airmax Ac Firmware<8.7.21
UI airMAX AC
All of the following
UI Airmax M Firmware<6.3.24
UI airMAX M
All of the following
UI Airfiber Af60-xg Firmware<1.2.3
UI Airfiber Af60-xg
All of the following
UI Airfiber Af60 Firmware<2.6.8
UI Airfiber Af60

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade airFiber AF60 to a version that resolves this vulnerability.

    Fixed in 2.6.8
  2. Upgrade

    Upgrade airFiber AF60-XG to a version that resolves this vulnerability.

    Fixed in 1.2.3
  3. Upgrade

    Upgrade airMAX AC to a version that resolves this vulnerability.

    Fixed in 8.7.21
  4. Upgrade

    Upgrade airMAX M to a version that resolves this vulnerability.

    Fixed in 6.3.24

Event History

Jan 8, 2026
CVE Published
via MITRE·04:14 PM
Data Sourced
via MITRE·04:14 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·05:15 PM
DescriptionSeverityWeaknessAffected Software
Aug 29, 58046
Event
via FIRST·12:02 AM
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Frequently Asked Questions

1

What is the severity of CVE-2026-21639?

CVE-2026-21639 has a high severity rating due to its potential for remote code execution.

2

How do I fix CVE-2026-21639?

To fix CVE-2026-21639, update your Ubiquiti airMAX AC to version 8.7.21 or later, and airMAX M to version 6.3.23 or later.

3

Which products are affected by CVE-2026-21639?

CVE-2026-21639 affects Ubiquiti airMAX AC (version 8.7.20 and earlier), airMAX M (version 6.3.22 and earlier), airFiber AF60-XG (version 1.2.2 and earlier), and airFiber AF60 (version 2.6.7 and earlier).

4

What type of attack can CVE-2026-21639 facilitate?

CVE-2026-21639 can facilitate a remote code execution attack if exploited.

5

Can CVE-2026-21639 be exploited from outside the Wi-Fi range?

CVE-2026-21639 requires the attacker to be within the Wi-Fi range of the affected product to exploit the vulnerability.

Company

Resources

Contact

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