CVE-2026-21634 Denial of service in UniFi Protect Application
An attacker on the adjacent network can cause a denial of service by overflowing the discovery protocol in the UniFi Protect Application.
- 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-2026-21634?
CVE-2026-21634 is a medium-severity denial of service vulnerability in Ubiquiti Inc UniFi Protect Application, published on 5 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 with access to the adjacent network could overflow the UniFi Protect Application (Version 6.1.79 and earlier) discovery protocol causing it to restart. Affected Products: UniFi Protect Application (Version 6.1.79 and earlier). Mitigation: Update your UniFi Protect Application to Version 6.2.72 or later.
Weakness: CWE-119
Which versions are affected by CVE-2026-21634?
It affects 1 product.
Products include Ui Unifi Protect.
How do I fix CVE-2026-21634?
No fix has been published for CVE-2026-21634 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-21634 being exploited?
There is no known exploitation of CVE-2026-21634 in the wild and no public exploit code.
Other vulnerabilities in Ubiquiti Inc UniFi Protect Application
- CVE-2026-55115 Server-side request forgery in UniFi Protect Application
- CVE-2021-22943 A vulnerability found in UniFi Protect application V1.18.1 and earlier permits a malicious actor who has already gained access to a network
- CVE-2026-56841 SQL injection in UniFi Protect Application
- CVE-2026-21633 Auth bypass in UniFi Protect Application
- CVE-2021-22957 Cross-site request forgery in UniFi Protect application
Sources
Also known as GHSA-w6v6-cxgj-7xh5.