Ubiquiti UniFi Building Bridge und Device Bridge: Schwachstelle ermöglicht Codeausführung
WID-SEC-2026-0022 · first 07.01.2026 · updated 09.01.2026 · CVSS 8,8
What it is about
UniFi ist Ubiquiti's End-to-End-Netzwerk-Ökosystem für Unternehmen und Smart Homes. Ein Angreifer aus einem angrenzenden Netzwerk kann eine Schwachstelle in Ubiquiti UniFi Building Bridge- und Device Bridge-Produkten ausnutzen, um beliebigen Programmcode auszuführen.
Under what conditions?
The BSI does not name any particular preconditions. Exploitable remotely according to the BSI.
What can happen in the worst case
An attacker could use the vulnerability to
- beliebigen Programmcode auszuführen
Am I affected?
Affected according to the BSI:
- Ubiquiti UniFi UBB-XG <1.2.3
- Ubiquiti UniFi UDB-Pro/UDB-Pro-Sector <1.4.2
- Ubiquiti UniFi UBB <3.1.7
The installed version is usually shown under “Help → About” or in the device’s admin interface.
What helps?
Update to at least:
- Ubiquiti UniFi UBB-XG 1.2.3
- Ubiquiti UniFi UDB-Pro/UDB-Pro-Sector 1.4.2
- Ubiquiti UniFi UBB 3.1.7
Is the vulnerability already being exploited?
None of the CVEs is in the CISA catalogue of exploited vulnerabilities. That does not mean there are no attacks, only that none are documented.
Information and sources
CVE: CVE-2026-21638
Source: BSI warning and information service (CERT-Bund); CISA. The assessment of the conditions is my reading of the BSI text; the external pages are in their original language.