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CVE-2026-34908 CISA KEV — actively exploited

Ubiquiti UniFi OS Improper Access Control Vulnerability

Ubiquiti Inc — UniFi OS Server

A malicious actor with access to the network could exploit an Improper Access Control vulnerability found in UniFi OS devices to make unauthorized changes to the system.

CVSS scoreCritical

10.0

EPSS — exploitation probabilityHigh

85.2%

Vector breakdown

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

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

Published
May 22, 2026
Modified
Jun 24, 2026
Added to KEV
Jun 23, 2026
Federal patch due
Jun 26, 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.

Weakness classification

Proof-of-concept & exploitation references

Public repositories whose name or description references CVE-2026-34908, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit — cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.

No public GitHub repositories referencing CVE-2026-34908 were found at last check. Absence here is not proof no exploit exists — see the references below for vendor advisories and write-ups.

References

How this class of flaw gets exploited

Frequently asked questions

What is CVE-2026-34908?

A malicious actor with access to the network could exploit an Improper Access Control vulnerability found in UniFi OS devices to make unauthorized changes to the system.

How severe is CVE-2026-34908?

CVE-2026-34908 has a CVSS base score of 10.0 out of 10 (CVSS 3.1).

Is CVE-2026-34908 actively exploited in the wild?

Yes. CVE-2026-34908 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Jun 23, 2026, meaning CISA has confirmed evidence of active exploitation.

What is the EPSS score for CVE-2026-34908?

85.2% - meaning FIRST.org's EPSS model estimates a 85.2% probability this vulnerability will be exploited in the wild within 30 days (100% percentile among all scored CVEs).

Is there exploit tooling available for CVE-2026-34908?

Yes - a public Nuclei template referencing CVE-2026-34908 exist in public repositories we checked.

What type of vulnerability is CVE-2026-34908?

CVE-2026-34908 is classified under CWE-284 (CWE-284 Improper Access Control - Generic).

Cross-checked against

Impactr finds and proves whether CVE-2026-34908 — or flaws like it — are actually reachable in your own web apps and APIs, with a reproducible exploit as evidence.