CVE-2026-34909: Ubiquiti UniFi OS Path Traversal Vulnerability
Vulnerability summary
CVE-2026-34909 is a critical (CVSS 10.0) Path Traversal vulnerability in Ubiquiti UniFi OS. It is known to be exploited: CISA lists it, first on 23-06-2026. EPSS estimates a 1.79% chance of exploitation in the next 30 days, higher than 78% of scored vulnerabilities. 1 public exploit is recorded.
Timeline
- 22-05-2026PublishedVulnerability first disclosed.
- 23-06-2026Added to CISA KEVUbiquiti UniFi OS Path Traversal Vulnerability
- 24-06-2026Last modifiedVulnerability information updated.
- 26-06-2026CISA remediation dueApply mitigations per vendor instructions.
Description
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.
CVSS metrics
2 scores · 2 sources · 1 version- NVDNIST10.0CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS trend
Probability
1.79%
Chance of exploitation in the next 30 days
Percentile
78%
Versus all other CVEs
30-day change
-63.25 pp
From 65.04% on 19-09-2026
Known exploited
Compare KEV catalogs
CISA KEVListed- Added
- 23-06-2026
- Federal due date
- 26-06-2026
CISA required action
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines. community.ui.com/releases/Security-Advisory-Bulletin-064-064/84811c09-4cf4-42ab-bd61-cc994445963b nvd.nist.gov/vuln/detail/CVE-2026-34909
Public exploits
1 foundExploit Reference (pwndefend.com)
Maturity: unknown
Weaknesses
CWE · root causeAffected systems
Ui32 products
- enterprise_fortress_gateway_firmware< 5.1.12
- enterprise_network_video_recorder_firmware< 5.1.12
- enterprise_network_video_recorder_core_firmware< 5.1.12
- unas_2_firmware< 5.1.10
- unas_4_firmware< 5.1.10
2 vendors · 64 products
References
3 links- www.pwndefend.com/2026/06/09/cve-2026-34910-exploitation-itw-building-a-botnet-mirai/Third Party AdvisoryExploit
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-34909Government ResourceUS Government Resource