Adjacent RCE via airMAX protocol buffer overflow
Published Jan 8, 2026 · Updated Jan 8, 2026
Buffer overflow in Ubiquiti airMAX and airFiber firmware allows physically proximate attackers to execute code via crafted wireless traffic. The airMAX Wireless Protocol handler copies attacker-controlled protocol data without checking its size; Ubiquiti has not disclosed the affected function or packet field. Wi-Fi range is required, and affected releases are airMAX AC 8.7.20 and earlier, airMAX M 6.3.22 and earlier, airFiber AF60-XG 1.2.2 and earlier, and airFiber AF60 2.6.7 and earlier.
Summary
What happened
Buffer overflow in Ubiquiti airMAX and airFiber firmware allows physically proximate attackers to execute code via crafted wireless traffic. The airMAX Wireless Protocol handler copies attacker-controlled protocol data without checking its size; Ubiquiti has not disclosed the affected function or packet field. Wi-Fi range is required, and affected releases are airMAX AC 8.7.20 and earlier, airMAX M 6.3.22 and earlier, airFiber AF60-XG 1.2.2 and earlier, and airFiber AF60 2.6.7 and earlier.
The record
- CVE
- CVE-2026-21639
- Published
- Jan 8, 2026
- Updated
- Jan 8, 2026
- Vendor
- Ubiquiti Inc.
- Product
- airFiber 60 XG
- Classifications
- CWE-77, CWE-120, T1210
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 8, 2026CVE publishedPublication date reported by the CVE source.
- Jan 8, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <1.2.3
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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