Is CVE-2026-34908 actively exploited?

Yes. Previdian has observed exploitation attempts targeting this CVE. Confidence is confirmed.

What exploitation activity has Previdian observed?

Previdian sensors have observed 6 exploitation attempts, 4 unique attacker IPs, and 2 countries targeting CVE-2026-34908. First observed Aug 13, 2026; last observed Oct 22, 2026.

Which versions are affected?

CVE-2026-34908 affects Ubiquiti UniFi OS Server and 30 other products. Previdian lists 31 version rows; examples include 0 to < 5.0.8 and 0 to < 5.1.12.

How should organizations remediate it?

Prioritize immediate patching and validate internet-facing exposure. Monitor for matching exploitation attempts in your environment.

Yes. CVE-2026-34908 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. Added to Previdian from a trusted third-party report 2 weeks before CISA listed it.

Vulnerability report

Active exploitation observed Confirmed confidence In CISA KEV

CVE-2026-34908

Q: What is CVE-2026-34908?

CVE-2026-34908 is an unauthenticated vulnerability affecting Ubiquiti UniFi OS Server and 30 other products. 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.

Q: How should organizations remediate it?

Prioritize immediate patching and validate internet-facing exposure. Monitor for matching exploitation attempts in your environment.

Q: Is it in CISA KEV?

Yes. CVE-2026-34908 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. Added to Previdian from a trusted third-party report 2 weeks before CISA listed it.

UniFi OS Server

Ubiquiti / UniFi OS Server · affected before 5.0.8

Watch CVE-2026-34908 Browse KEV feed

Severity: CVSS 10.0 · Critical
Confidence: Confirmed
Exploit status: Observed in sensors
EPSS: 15.2%
First observed: 13 Aug 2026
Last observed: 22 Oct 2026

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-34908 is an unauthenticated vulnerability affecting Ubiquiti UniFi OS Server and 30 other products. A malicious actor with access to the network could exploit an Improper Access Control vulnerability found in...

Is it exploited?

Yes. Previdian sensors observed exploitation attempts with confirmed confidence. Listed in CISA KEV. Also confirmed by third-party sources.

Who is affected?

Ubiquiti / UniFi OS Server affected before 5.0.8.

What should we do?

Patch immediately, validate internet-facing exposure, and monitor for matching requests.

Overview

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.

Vendor Product Affected Status

Ubiquiti Inc Affected

UniFi OS Server

Before 5.0.8

Affected

Ubiquiti Inc Affected

UDM

Before 5.1.12

Affected

Ubiquiti Inc Affected

UDM-Pro

Before 5.1.12

Affected

Ubiquiti Inc Affected

UDM-SE

Before 5.1.12

Affected

Ubiquiti Inc Affected

UDM-Pro-Max

Before 5.1.12

Affected

Ubiquiti Inc Affected

UDM-Beast

Before 5.1.11

Affected

Ubiquiti Inc Affected

EFG

Before 5.1.12

Affected

Ubiquiti Inc Affected

UDW

Before 5.1.12

Affected

Ubiquiti Inc Affected

UDR

Before 5.1.12

Affected

Ubiquiti Inc Affected

UDR7

Before 5.1.12

Affected

Ubiquiti Inc Affected

UDR-5G

Before 5.1.12

Affected

Ubiquiti Inc Affected

Express 7

Before 5.1.12

Affected

Ubiquiti Inc Affected

UNVR

Before 5.1.12

Affected

Ubiquiti Inc Affected

UNVR-Pro

Before 5.1.12

Affected

Ubiquiti Inc Affected

UNVR-Instant

Before 5.1.12

Affected

Ubiquiti Inc Affected

UNVR-G2

Before 5.1.12

Affected

Ubiquiti Inc Affected

UNVR-G2-Pro

Before 5.1.12

Affected

Ubiquiti Inc Affected

ENVR

Before 5.1.12

Affected

Ubiquiti Inc Affected

ENVR-Core

Before 5.1.12

Affected

Ubiquiti Inc Affected

UNAS-2

Before 5.1.10

Affected

Ubiquiti Inc Affected

UNAS-4

Before 5.1.10

Affected

Ubiquiti Inc Affected

UNAS-Pro

Before 5.1.10

Affected

Ubiquiti Inc Affected

UNAS-Pro-4

Before 5.1.10

Affected

Ubiquiti Inc Affected

UNAS-Pro-8

Before 5.1.10

Affected

Ubiquiti Inc Affected

UCKP

Before 5.1.12

Affected

Ubiquiti Inc Affected

UCK

Before 5.1.12

Affected

Ubiquiti Inc Affected

UCK-Enterprise

Before 5.1.12

Affected

Ubiquiti Inc Affected

UCG-Ultra

Before 5.1.12

Affected

Ubiquiti Inc Affected

UCG-Max

Before 5.1.12

Affected

Ubiquiti Inc Affected

UCG-Fiber

Before 5.1.12

Affected

Ubiquiti Inc Affected

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-2026-34908
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 Previdian 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

A trusted third party reported exploitation.

Active exploitation observed

Previdian sensor

First observed 13 Aug 2026

Previdian first observed exploitation attempts targeting this vulnerability in our honeypot sensors.

Proof of concept available

GitHub

Recorded 05 Jun 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

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

Learn about Pro API access

Source	Added
Defused Cyber First	2026-06-09 07:27 UTC
CISA	2026-06-23 00:00 UTC
CVE	2026-06-23 18:11 UTC
All CISA Advisories	2026-06-23 18:20 UTC
Previdian Sensors	2026-08-13 09:05 UTC
The Hacker News	2026-09-22 11:31 UTC

Operational indicators for this CVE are listed under Detection.

Sensor telemetry

First-party evidence of exploitation activity

Previdian sensors recorded exploitation attempts targeting this vulnerability. The cards and chart show volume, unique attackers, and daily activity.

Attempts observed

Unique attacker IPs

Attacker countries

NL · US

Sensors observed

CVE-2026-34908 exploitation attempts over the last 72 days

Daily events observed by Previdian sensors

Updated 22 Oct 2026

12 Aug 27 Aug 11 Sep 26 Sep 22 Oct

First observed 13 Aug 2026 · Last observed 22 Oct 2026

Pro adds sensor region and window summaries. Enterprise adds raw IPs, paths, User-Agents, and payloads.

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Detection

Operational artifacts and observed signals

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

Observed signals

Request targets
User-Agents
Callback hosts: 1; 1; 0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Scanner coverage

Nuclei template detected 11 Aug 2026.

View Nuclei template

Virtual patch status

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

Learn about virtual patches →

Attacker IP Indicators

Attacker IP indicators observed · available in Pro and Enterprise.

Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.

Learn about Pro API access

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner	Reference	Detected
Nuclei	https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-34908.yaml	11 Aug 2026

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

10.0 Critical

Potential damage if exploited. Separate from whether attackers are using it.

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

EPSS

15.2%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Improper Access Control CWE-284

Recent mention · The Hacker News

22 Sep 2026

Zyxel and Veeam Flaws Under Active Exploitation With Command and SYSTEM Access

Read full advisory

All Mentions

Recent mention · The Hacker News

Zyxel and Veeam Flaws Under Active Exploitation With Command and SYSTEM Access

The Hacker News · 22 Sep 2026

Ravie LakshmananSep 22, 2026Vulnerability / Endpoint Security The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Monday added a now-patched security flaw impacting Zyxel GS1900 series switches to its Known Exploited Vulnerabilities (KEV) catalog, citing evidence of active exploitation. The vulnerability, tracked as CVE-2026-7273 (CVSS score: 8.8), is a stack-based buffer overflow vulnerability that could result in arbitrary operating system (OS) command execution. "A stack-based buffer overflow vulnerability in the CGI program of the Zyxel GS1900 series switch firmware...

Recent mention · GreyNoise

Open Season on Kapibala: Attacker Steals Over 18,000 Government Records Through WordPress Exploitation

GreyNoise · 21 Sep 2026

GreyNoise has been tracking malicious use of an IP address since early June 2026 due to its frequent use in scans and attacks against a variety of technologies. We detail a few of the more notable intrusions we observed including the theft of more than 18,000 sensitive records from a western government.

Recent mention · All CISA Advisories

CISA Adds Four Known Exploited Vulnerabilities to Catalog

All CISA Advisories · 23 Jun 2026

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 Vulnerability CVE-2026-34909 Ubiquiti UniFi OS Path Traversal Vulnerability CVE-2026-34910 Ubiquiti UniFi OS Improper Input Validation Vulnerability These types of vulnerabilities are frequent attack vectors for malicious cyber actors and pose significant risks to the federal enterprise. Binding Operational Directive (BOD) 26-04:...

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

UniFi OS - Authentication Bypass via Path Traversal (..%2f)

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

22 Sep 2026
11:31 UTC

KEV confirmed by The Hacker News

Exploitation attested by an external source
13 Aug 2026
09:04 UTC

Indicators of compromise added (4)

Indicators of compromise recorded
13 Aug 2026
09:04 UTC

Observed by Previdian sensors

Evidence-backed exploitation signal
11 Aug 2026
04:31 UTC

Public PoC available

Public proof-of-concept code published
11 Aug 2026
04:31 UTC

Nuclei template available

Scanner coverage available
23 Jun 2026
18:20 UTC

KEV confirmed by All CISA Advisories

Exploitation attested by an external source
23 Jun 2026
18:11 UTC

KEV confirmed by CVE

Exploitation attested by an external source
23 Jun 2026
00:00 UTC

Added to CISA KEV

Listed in the CISA Known Exploited Vulnerabilities catalog
09 Jun 2026
07:27 UTC

Added to Previdian KEV Feed

High-confidence, third-party attested exploitation
22 May 2026
00:43 UTC

CVE published

Vulnerability disclosed publicly
31 Mar 2026
15:00 UTC

CVE ID reserved

Identifier reserved by the CNA

Pro API

Automate this intelligence

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-2026-34908

Sample API response

{
  "cve_id": "CVE-2026-34908",
  "confidence": "Confirmed",
  "cvss_score": 10.0,
  "cvss_estimated": false,
  "epss_score": 0.15207,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "attempts": 6, "sensors": 4 }
}

CVE-2026-34908

UniFi OS Server

Tags

CVE References

Exploited in the wild

Active exploitation observed

Proof of concept available

Known exploited vulnerability sources

Observed signals

Scanner coverage

Virtual patch status

Attacker IP Indicators

Scanner Artifacts

Weaknesses

Zyxel and Veeam Flaws Under Active Exploitation With Command and SYSTEM Access

All Mentions

Potential Proof of Concepts

KEV confirmed by The Hacker News

Indicators of compromise added (4)

Observed by Previdian sensors

Public PoC available

Nuclei template available

KEV confirmed by All CISA Advisories

KEV confirmed by CVE

Added to CISA KEV

Added to Previdian KEV Feed

CVE published

CVE ID reserved

Automate this intelligence