by Kastro
Paper/Archive/CVE-2026-34909

CVE-2026-34909

Ubiquiti Inc UniFi OS Server — Ubiquiti UniFi OS Path Traversal Vulnerability

KEV · due 26 JunEPSS 68%public exploitSSVC actCVSS 10.0
critical.is priorityof 100
100
CVSS 10.0 (CNA)10.0 / 10 × 3030.0In CISA KEV+3030.0EPSS percentile 99.3.993 × 2019.9Exploit: SSVC active+1010.0SSVC exploitation: active+1010.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
UniFi OS Server< 5.0.85.0.8CNA
Express< 4.0.144.0.14CNA
UDM< 5.1.125.1.12CNA
UDM-Pro< 5.1.125.1.12CNA
UDM-SE< 5.1.125.1.12CNA
UDM-Pro-Max< 5.1.125.1.12CNA
UDM-Beast< 5.1.115.1.11CNA
EFG< 5.1.125.1.12CNA
UDW< 5.1.125.1.12CNA
UDR< 5.1.125.1.12CNA
UDR7< 5.1.125.1.12CNA
UDR-5G< 5.1.125.1.12CNA

Scores by source

hackerone (CNA)10.0CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: active · Automatable: yes · Technical impact: total

References

refcommunity.ui.com/releases/Security-Advisory-Bulletin-064-064/84811c09-4cf4-42ab-bd61-cc994445963bwriteuppwndefend.com/2026/06/09/cve-2026-34910-exploitation-itw-building-a-botnet-mirairefcisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-34909kevcisa.gov/known-exploited-vulnerabilities-catalog