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8.8
HIGH CVSS 3.1
CVE-2026-21639
Ubiquiti airMAX Remote Code Execution Vulnerability
Overview
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.

Details
INFO

Published Date :

Jan. 8, 2026, 5:15 p.m.

Last Modified :

July 30, 2026, 6:25 a.m.

Remotely Exploit :

No

Source :

[email protected]
Impact
Affected Products

The following products are affected by CVE-2026-21639 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Ui airmax_ac_firmware
2 Ui airmax_ac
3 Ui airmax_m
4 Ui airmax_m_firmware
5 Ui airfiber_af60-xg_firmware
6 Ui airfiber_af60-xg
7 Ui airfiber_af60_firmware
8 Ui airfiber_af60
: Total Affected Vendor : 1 | Products : 8
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 MEDIUM 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH [email protected]
Solution
Update affected devices to the latest firmware versions to prevent remote code execution.
  • Update airMAX AC to version 8.7.21 or later.
  • Update airMAX M to version 6.3.24 or later.
  • Update airFiber AF60-XG to version 1.2.3 or later.
  • Update airFiber AF60 to version 2.6.8 or later.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-21639.

URL Resource
https://community.ui.com/releases/Security-Advisory-Bulletin-061-061/1e4fe5f8-29c7-4a7d-a518-01b1537983ba Vendor Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-21639 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-21639 weaknesses.

CAPEC-15: Command Delimiters Command Delimiters CAPEC-40: Manipulating Writeable Terminal Devices Manipulating Writeable Terminal Devices CAPEC-43: Exploiting Multiple Input Interpretation Layers Exploiting Multiple Input Interpretation Layers CAPEC-75: Manipulating Writeable Configuration Files Manipulating Writeable Configuration Files CAPEC-76: Manipulating Web Input to File System Calls Manipulating Web Input to File System Calls CAPEC-136: LDAP Injection LDAP Injection CAPEC-183: IMAP/SMTP Command Injection IMAP/SMTP Command Injection CAPEC-248: Command Injection Command Injection CAPEC-8: Buffer Overflow in an API Call Buffer Overflow in an API Call CAPEC-9: Buffer Overflow in Local Command-Line Utilities Buffer Overflow in Local Command-Line Utilities CAPEC-10: Buffer Overflow via Environment Variables Buffer Overflow via Environment Variables CAPEC-14: Client-side Injection-induced Buffer Overflow Client-side Injection-induced Buffer Overflow CAPEC-24: Filter Failure through Buffer Overflow Filter Failure through Buffer Overflow CAPEC-42: MIME Conversion MIME Conversion CAPEC-44: Overflow Binary Resource File Overflow Binary Resource File CAPEC-45: Buffer Overflow via Symbolic Links Buffer Overflow via Symbolic Links CAPEC-46: Overflow Variables and Tags Overflow Variables and Tags CAPEC-47: Buffer Overflow via Parameter Expansion Buffer Overflow via Parameter Expansion CAPEC-67: String Format Overflow in syslog() String Format Overflow in syslog() CAPEC-92: Forced Integer Overflow Forced Integer Overflow CAPEC-100: Overflow Buffers Overflow Buffers

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-21639 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-21639 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    Jul. 30, 2026

    Action Type Old Value New Value
    Changed 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. Affected Products: 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) airFiber AF60 (Version 2.6.7 and earlier) Mitigation: Update your airMAX AC to Version 8.7.21 or later. Update your airMAX M to Version 6.3.24 or later. Update your airFiber AF60-XG to Version 1.2.3 or later. Update your airFiber AF60 to Version 2.6.8 or later. 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.
    Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-120
  • CVE Modified by [email protected]

    Jun. 17, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'Ubiquiti Inc', 'product': 'airMAX AC', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '8.7.21', 'versionType': 'semver'}], 'defaultStatus': 'unaffected'}, {'vendor': 'Ubiquiti Inc', 'product': 'airMAX M', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '6.3.24', 'versionType': 'semver'}], 'defaultStatus': 'unaffected'}, {'vendor': 'Ubiquiti Inc', 'product': 'airFiber AF60-XG', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '1.2.3', 'versionType': 'semver'}], 'defaultStatus': 'unaffected'}, {'vendor': 'Ubiquiti Inc', 'product': 'airFiber AF60', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '2.6.8', 'versionType': 'semver'}], 'defaultStatus': 'unaffected'}]
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jun. 17, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-21639', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-01-08T17:09:52.634464Z'}
  • Initial Analysis by [email protected]

    Jan. 14, 2026

    Action Type Old Value New Value
    Added CPE Configuration AND OR *cpe:2.3:o:ui:airmax_ac_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 8.7.21 OR cpe:2.3:h:ui:airmax_ac:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ui:airmax_m_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 6.3.24 OR cpe:2.3:h:ui:airmax_m:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ui:airfiber_af60-xg_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.2.3 OR cpe:2.3:h:ui:airfiber_af60-xg:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ui:airfiber_af60_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.6.8 OR cpe:2.3:h:ui:airfiber_af60:-:*:*:*:*:*:*:*
    Added Reference Type HackerOne: https://community.ui.com/releases/Security-Advisory-Bulletin-061-061/1e4fe5f8-29c7-4a7d-a518-01b1537983ba Types: Vendor Advisory
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jan. 08, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
    Added CWE CWE-77
  • New CVE Received by [email protected]

    Jan. 08, 2026

    Action Type Old Value New Value
    Added 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. Affected Products: 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) airFiber AF60 (Version 2.6.7 and earlier) Mitigation: Update your airMAX AC to Version 8.7.21 or later. Update your airMAX M to Version 6.3.24 or later. Update your airFiber AF60-XG to Version 1.2.3 or later. Update your airFiber AF60 to Version 2.6.8 or later.
    Added Reference https://community.ui.com/releases/Security-Advisory-Bulletin-061-061/1e4fe5f8-29c7-4a7d-a518-01b1537983ba
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 8.8
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact