Cyber Resilience

CVE-2026-33000

CriticalUpdated

Published: 22 May 2026

Published
22 May 2026
Modified
24 June 2026
KEV Added
Patch
CVSS Score v3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0125 65.7th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-33000 is a critical-severity Improper Input Validation (CWE-20) vulnerability in Ui Unifi Os Server. Its CVSS base score is 9.1 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 34.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

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

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
Why these techniques?

Network-accessible improper input validation on UniFi OS directly enables remote command injection (T1190) leading to arbitrary command execution via shell interpreter (T1059.001).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-34910Same product: Ui Unifi Os Server
CVE-2026-34909Same product: Ui Unifi Os Server
CVE-2025-52665Same vendor: Ui
CVE-2026-34908Same product: Ui Unifi Os Server
CVE-2025-59467Same vendor: Ui
CVE-2026-34911Same product: Ui Unifi Os Server
CVE-2026-21638Same vendor: Ui
CVE-2025-48913Shared CWE-20
CVE-2025-67484Shared CWE-20
CVE-2026-4755Shared CWE-20

Affected Assets

ui
unifi os server
≤ 5.0.8

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-20

Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.

addresses: CWE-20

Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.

addresses: CWE-20

Directly implements checks on information inputs to reject invalid data before processing.

addresses: CWE-20

Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.

References