CVE-2026-77543
CriticalA malicious actor with access to the network and low privileges could exploit an Improper Input Validation vulnerability found in UniFi Access Application to execute a Command Injection on the host device.
Published Aug 26, 2026 · Updated Aug 28, 2026 · Also known as EUVD-2026-66384, GHSA-xf5j-wgpj-6w8j
Key Facts
Patch in the next maintenance window- CVE-2026-77543 is a critical-severity vulnerability (CVSS 9.9 v3.1) affecting UniFi Access Application.
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- EPSS estimates a 1.4% probability of exploitation in the next 30 days.
- Fixed versions are available, including UniFi Access Application 4.3.5.
- Brandefense priority: patch in the next maintenance window, because of its high severity, although no exploitation is known.
CVSS v3.1
9.9
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
1.4%
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
None known
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Description
A malicious actor with access to the network and low privileges could exploit an Improper Input Validation vulnerability found in UniFi Access Application to execute a Command Injection on the host device.
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| UniFi Access Application | See advisory | 4.3.5 |
Patched Releases
UniFi Access Application
4.3.5
Timeline
Publicly disclosed
Aug 26, 2026
Last updated
Aug 28, 2026
Weakness Type
- CWE-20 Improper Input Validation
References
FAQ
Common Questions.
A malicious actor with access to the network and low privileges could exploit an Improper Input Validation vulnerability found in UniFi Access Application to execute a Command Injection on the host device.
Affected: UniFi Access Application. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including UniFi Access Application 4.3.5.
Brandefense priority: patch in the next maintenance window, because of its high severity, although no exploitation is known.
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