CVE-2026-21639: ubiquiti inc airfiber af60 Classic Buffer Overflow

Vulnerability summary

CVE-2026-21639 is a high (CVSS 8.8) Classic Buffer Overflow vulnerability in ubiquiti inc airfiber af60. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 31.8% of scored vulnerabilities.

Timeline

1. 08-01-2026
   PublishedVulnerability first disclosed.
2. 30-07-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
• CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.