SB2026022728 - Multiple vulnerabilities in Ubiquiti Networks UniFi Protect Application

Description

This security bulletin contains information about 2 vulnerabilities.

1) Improper Authentication (CVE-ID: CVE-2026-21633)

CWE-ID: CWE-287 - Improper Authentication

CVSSv4: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to the lack of encryption in the communications channel within the discovery protocol. A remote attacker on the local network can bypass authentication process and gain unauthorized access to the application.

2) Buffer overflow (CVE-ID: CVE-2026-21634)

CWE-ID: CWE-119 - Memory corruption

CVSSv4: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error within the parsing of WebSocket headers. A remote attacker on the local network can trigger memory corruption and cause a denial of service condition on the target system.

Remediation

Install update from vendor's website.

References

• https://www.zerodayinitiative.com/advisories/ZDI-26-126/
• https://community.ui.com/releases/Security-Advisory-Bulletin-058-058/6922ff20-8cd7-4724-8d8c-676458a2d0f9
• https://www.zerodayinitiative.com/advisories/ZDI-26-127/
• https://www.zerodayinitiative.com/advisories/ZDI-26-128/