VDB-395744 · CVE-2026-77543 · EUVD-2026-66384

Ubiquiti Access Application up to 4.3.4 input validation

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
9.7	$0-$5k	1.80

Summaryinfo

A vulnerability was found in Ubiquiti Access Application up to 4.3.4. It has been declared as very critical. This affects an unknown function. Such manipulation leads to input validation. This vulnerability is traded as CVE-2026-77543. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in Ubiquiti Access Application up to 4.3.4 and classified as very critical. Affected by this issue is some unknown processing. The manipulation with an unknown input leads to a input validation vulnerability. Using CWE to declare the problem leads to CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at community.ui.com. This vulnerability is handled as CVE-2026-77543 since 08/20/2026. The exploitation is known to be easy. The attack may be launched remotely. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/26/2026).

Upgrading to version 4.3.5 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-66384). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

Ubiquiti

Name

Access Application

Version

License

commercial

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.9
VulDB Meta Temp Score: 9.7

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 9.9
CNA Vector (Ubiquiti): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Access Application 4.3.5

Timelineinfo

08/20/2026 CVE reserved
08/26/2026 +6 days Advisory disclosed
08/26/2026 +0 days VulDB entry created
08/26/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: community.ui.com
Status: Confirmed

CVE: CVE-2026-77543 (🔒)
GCVE (CVE): GCVE-0-2026-77543
GCVE (VulDB): GCVE-100-395744
EUVD: 🔒

Entryinfo

Created: 08/26/2026 12:34
Updated: 08/26/2026 14:43
Changes: 08/26/2026 12:34 (62), 08/26/2026 14:43 (1)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.