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Vulnerability Intelligence

CVE-2026-34909

CriticalExploitedPublic exploit

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.

Published May 22, 2026 · Updated Jul 23, 2026

Key Facts

Patch immediately
  • CVE-2026-34909 is a critical-severity vulnerability (CVSS 10.0 v3.1) affecting UniFi OS Server (Ui), Enterprise Fortress Gateway Firmware (Ui), Enterprise Network Video Recorder Core Firmware (Ui) and 22 more products.
  • It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jun 9, 2026. Public exploit code is available.
  • EPSS estimates a 1.8% probability of exploitation in the next 30 days.
  • Fixed versions are available, including EFG 5.1.12, ENVR 5.1.12, ENVR-Core 5.1.12.
  • Brandefense priority: patch immediately, because it is listed as exploited in the wild.

CVSS v3.1

10.0

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

EPSS (30-day exploit likelihood)

1.8%

Higher than 78.0% of all scored CVEs

Exploited in the wild

Yes

4 catalog listings

Public exploit code

Available

Proof-of-concept or weaponized module

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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.

Known-Exploited Catalog Listings

CatalogAddedRemediation dueRansomware use
CISA KEVJun 23, 2026Jun 26, 2026Not reported
Industry KEV feedJun 9, 2026Jun 26, 2026Not reported
CIRCL KEVJun 9, 2026Jun 26, 2026Not reported
ENISA EUVDJun 23, 2026n/aNot reported

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.

Affected Products

64 affected entries in total
ProductAffected versionsFixed in
UniFi OS ServerUiSee advisory5.0.8
Enterprise Fortress Gateway FirmwareUiSee advisory5.1.12
Enterprise Network Video Recorder Core FirmwareUiSee advisory5.1.12
Enterprise Network Video Recorder FirmwareUiSee advisory5.1.12
Unas 2 FirmwareUiSee advisory5.1.10
20 more affected products in the full CVE brief

Patched Releases

EFG

5.1.12

ENVR

5.1.12

ENVR-Core

5.1.12

Express

4.0.14

Express 7

5.1.12

UCG-Fiber

5.1.12

UCG-Industrial

5.1.12

UCG-Max

5.1.12

UCG-Ultra

5.1.12

UCK

5.1.12

UCK-Enterprise

5.1.12

UCKP

5.1.12

UDM

5.1.12

UDM-Beast

5.1.11

UDM-Pro

5.1.12

UDM-Pro-Max

5.1.12

UDM-SE

5.1.12

UDR

5.1.12

UDR-5G

5.1.12

UDR7

5.1.12

UDW

5.1.12

Enterprise Fortress Gateway Firmware

5.1.12

Enterprise Network Video Recorder Core Firmware

5.1.12

Enterprise Network Video Recorder Firmware

5.1.12

Unas 2 Firmware

5.1.10

Timeline

  1. Publicly disclosed

    May 22, 2026

  2. Added to Industry KEV feed

    Jun 9, 2026

  3. Added to CIRCL KEV

    Jun 9, 2026

  4. Added to CISA KEV

    Jun 23, 2026

  5. Added to ENISA EUVD

    Jun 23, 2026

  6. Last updated

    Jul 23, 2026

Weakness Type

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

References

4 more references in the full CVE brief

FAQ

Common Questions.

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