What is CVE-2026-21639?

CVE-2026-21639 is a medium-severity vulnerability in Ubiquiti Inc Airfiber Af60, classified under Command Injection. CVSS score: 5.4/10. Published 2026-01-08.

How severe is CVE-2026-21639?

Medium severity. CVSS v3 base score is 5.4 out of 10.

RCE in Ubiquiti Inc Airfiber Af60

CVE-2026-21639

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 Products: airMAX AC (Version…

Vulnerability class: Command Injection (OS Command Injection)

EPSS: 0.003 (18.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

Affected products

Ubiquiti Inc Airfiber Af60 — versions 0
Ubiquiti Inc Airfiber Af60-xg — versions 0
Ubiquiti Inc Airmax Ac — versions 0
Ubiquiti Inc Airmax M — versions 0
Ui Airfiber_af60
Ui Airfiber_af60_firmware
Ui Airfiber_af60-xg
Ui Airfiber_af60-xg_firmware
Ui Airmax_ac
Ui Airmax_ac_firmware

Weakness classification (CWE)

CWE-77 — Command Injection

References

support@hackerone.com (Vendor Advisory)

Frequently asked questions

What is CVE-2026-21639?: CVE-2026-21639 is a medium-severity vulnerability in Ubiquiti Inc Airfiber Af60, classified under Command Injection. CVSS score: 5.4/10. Published 2026-01-08.
How severe is CVE-2026-21639?: Medium severity. CVSS v3 base score is 5.4 out of 10.