CVE-2026-77540

CriticalCVSS 9.1

Published: 26/08/2026(UTC)Updated: 28/08/2026(UTC)Translated: 26/08/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Elevated risk

0.81%

54th percentile - higher than 54% of all known CVEs

Summary

An attacker with network access and high privileges can exploit an improper input validation vulnerability in UniFi OS Server to execute a command injection on the host device.

Risk Assessment

Risk of arbitrary command execution on the host, potentially leading to full server compromise.

Recommendation

Update UniFi OS Server to the latest version and restrict network access to the server.

Other vulnerabilities in UniFi OS Server

CVE-2026-77539Critical
An attacker with network access and high privileges can exploit an improper input validation vulnerability in UniFi OS Server to execute a command injection on the host device.

Original NVD description (English source)

A malicious actor with access to the network and high privileges could exploit an Improper Input Validation vulnerability found in UniFi OS Server to execute a Command Injection on the host device.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS