Is CVE-2026-34909 actively exploited?

Yes. KEV Intelligence tracks CVE-2026-34909 as a known exploited vulnerability. Confidence is confirmed.

What exploitation activity has KEV Intelligence observed?

KEV Intelligence has not yet recorded sensor-observed exploitation attempts for CVE-2026-34909. Our sensors continue to monitor for activity targeting this CVE.

Which versions are affected?

CVE-2026-34909 affects Ubiquiti Inc UniFi OS Server and 31 other products. KEV Intelligence lists 32 version rows; examples include 0 to < 5.0.8, 0 to < 4.0.14, and 0 to < 5.1.12.

Yes. CVE-2026-34909 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. KEV Intelligence attested it 14 days ahead of CISA.

CVE-2026-34909 Exploited in the Wild — UniFi OS Server, Express, UDM, UDM-Pro, UDM-SE, UDM-Pro-Max, UDM-Beast, EFG, UDW, UDR, UDR7, UDR-5G, Express 7, UNVR, UNVR-Pro, UNVR-Instant, UNVR-G2, UNVR-G2-Pro, ENVR, ENVR-Core, UNAS-2, UNAS-4, UNAS-Pro, UNAS-Pro-4, UNAS-Pro-8, UCKP, UCK, UCK-Enterprise, UCG-Ultra, UCG-Max, UCG-Fiber, UCG-Industrial

Q: What is CVE-2026-34909?

CVE-2026-34909 is an unauthenticated vulnerability affecting Ubiquiti Inc UniFi OS Server and 31 other products. A malicious actor with access to the network could exploit a Path Traversal vulnerability found in UniFi OS devices to access files on the underlying system that could be manipulated to access an underlying account.

Q: How should organizations remediate it?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Q: Is it in CISA KEV?

Yes. CVE-2026-34909 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. KEV Intelligence attested it 14 days ahead of CISA.

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-34909 is an unauthenticated vulnerability affecting Ubiquiti Inc UniFi OS Server and 31 other products. A malicious actor with access to the network could exploit a Path Traversal vulnerability found in UniFi...

Is it exploited?

Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.

Who is affected?

Ubiquiti Inc / UniFi OS Server affected before 5.0.8.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

UniFi OS Server Path Traversal

A malicious actor with access to the network could exploit a Path Traversal vulnerability found in UniFi OS devices to access files on the underlying system that could be manipulated to access an underlying account.

Vendor Product Affected Status

Ubiquiti Inc UCKP Before 5.1.12 Affected

Ubiquiti Inc UCK Before 5.1.12 Affected

Ubiquiti Inc UCK-Enterprise Before 5.1.12 Affected

Ubiquiti Inc UCG-Ultra Before 5.1.12 Affected

Ubiquiti Inc UCG-Max Before 5.1.12 Affected

Ubiquiti Inc UCG-Fiber Before 5.1.12 Affected

Ubiquiti Inc UCG-Industrial Before 5.1.12 Affected

Published: 22 May 2026
Exploitation Reported: 09 Jun 2026
Attack vector: Remote
Complexity: Low
Privileges: None
User interaction: None

CVE References

CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2026-34909
community.ui.com/releases/Security-Advisory-Bulletin-064-064/... community.ui.com · CVE Record https://community.ui.com/releases/Security-Advisory-Bulletin-064-064/...

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

Defused Cyber

Recorded 09 Jun 2026

Independent exploitation attestation added to the KEV Intelligence record.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

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Source	Added
Defused Cyber First	2026-06-09 07:29 UTC
CISA	2026-06-23 00:00 UTC
CVE	2026-06-23 18:11 UTC
All CISA Advisories	2026-06-23 18:20 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets: 0
User-Agents: 0

Raw values available in Pro and Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

No detection artifacts or sensor request patterns are available for this CVE yet.

Check back as sensor telemetry and scanner integrations are updated.

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

10.0 Critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS

63.9%

Weaknesses

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') CWE-22

Recent mention · All CISA Advisories

CISA Adds Four Known Exploited Vulnerabilities to Catalog

CISA has added four new vulnerabilities to its Known Exploited Vulnerabilities (KEV) Catalog, based on evidence of active exploitation. CVE-2025-67038 Lantronix EDS5000 Code Injection Vulnerability CVE-2026-34908 Ubiquiti UniFi OS Improper Access Control...

Read full advisory

Timeline

From disclosure to observed exploitation

23 Jun 2026
KEV confirmed by All CISA Advisories

Exploitation attested by an external source
23 Jun 2026
KEV confirmed by CVE

Exploitation attested by an external source
23 Jun 2026
Added to CISA KEV

Listed in the CISA Known Exploited Vulnerabilities catalog
09 Jun 2026
Added to KEV Intelligence KEV Feed

High-confidence, third-party attested exploitation
22 May 2026
CVE published

Vulnerability disclosed publicly
31 Mar 2026
CVE ID reserved

Identifier reserved by the CNA

Pro API

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Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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Evidence confidence and provenance
First-party sensor telemetry
PoC and scanner references
Affected versions and enrichment
Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-34909

Free JSON includes basic KEV fields

{
  "cve_id": "CVE-2026-34909",
  "confidence": "Confirmed",
  "cvss_score": 10.0,
  "cvss_estimated": false,
  "epss_score": 0.63897,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}

CVE-2026-34909

What security teams need to know first

UniFi OS Server Path Traversal

Tags

CVE References

Why KEV Intelligence marks this CVE as exploited

Exploited in the wild

Known exploited vulnerability sources

Operational artifacts and observed signals

Observed signals

Scanner coverage

Virtual patch status

Severity, weaknesses, and research context

Weaknesses

CISA Adds Four Known Exploited Vulnerabilities to Catalog

From disclosure to observed exploitation

KEV confirmed by All CISA Advisories

KEV confirmed by CVE

Added to CISA KEV

Added to KEV Intelligence KEV Feed

CVE published

CVE ID reserved

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