Threat Intelligence / CVE / CVE-2026-33000

CVE-2026-33000 — Ubiquiti Inc UniFi OS Server

CVSS v3.1 9.1 (CRITICAL) · EPSS 0.0% (higher than 19.8% of all scored CVEs) · Priority 5.3/10 · Published 2026-05-22

As of 2026-05-23, CVE-2026-33000 is a CRITICAL-severity vulnerability in Ubiquiti Inc UniFi OS Server, CVSS v3.1 9.1, EPSS 0.0% (19.8th percentile). Threadlinqs Intelligence links 2 tracked threat campaigns to CVE-2026-33000, most recently “UniFi OS Server Pre-Auth RCE Chain (CVE-2026-34908/34909/34910): x-original-uri Auth-Gateway Bypass + package-update Command Injection”.

Last updated: 2026-05-23

What is CVE-2026-33000?

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.

The record classifies CVE-2026-33000 under weakness class CWE-20. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs high-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 113 days ago.

Severity and exploitation probability

CVSS v3.1 base score
9.1 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
EPSS (FIRST)
0.0% probability of exploitation in the next 30 days, higher than 19.8% of all scored CVEs
CISA KEV
Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority
5.3/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published
2026-05-22, last modified 2026-05-23

Is CVE-2026-33000 being exploited?

It currently carries a trending score of 12 in the Threadlinqs vulnerability feed.

Affected products and versions

How to fix CVE-2026-33000

No vendor patch reference has been recorded for CVE-2026-33000 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

Threat activity tracking CVE-2026-33000

2 tracked threats in the Threadlinqs corpus reference CVE-2026-33000, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Seeded from cveorg and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.

Full detection coverage & IOCs for threats exploiting CVE-2026-33000 are available via the Threadlinqs MCP server (Purple tier). View plans →

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