CVE-2026-21638 Command injection in UBB
A remote attacker in Wi-Fi range can execute arbitrary code on Ubiquiti wireless bridges via a vulnerability in the airMAX protocol.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-21638?
CVE-2026-21638 is a high-severity command injection vulnerability in Ubiquiti Inc UBB, published on 8 Jan 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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: UBB-XG (Version 1.2.2 and earlier) UDB-Pro/UDB-Pro-Sector (Version 1.4.1 and earlier) UBB (Version 3.1.5 and earlier) Mitigation: Update your UBB-XG to Version 1.2.3 or later. Update your UDB-Pro/UDB-Pro-Sector to Version 1.4.2 or later. Update your UBB to Version 3.1.7 or later.
Weakness: CWE-77
Which versions are affected by CVE-2026-21638?
It affects 4 products.
Products include Ui Ubb-Xg Firmware, Ui Ubb Firmware, Ui Udb-Pro-Sector Firmware, Ui Udb-Pro Firmware.
How do I fix CVE-2026-21638?
No fix has been published for CVE-2026-21638 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-21638 being exploited?
There is no known exploitation of CVE-2026-21638 in the wild and no public exploit code.
Sources
Also known as GHSA-m92x-4jg5-v4px.