Vulnerability report

Active exploitation observed Confirmed confidence In CISA KEV

CVE-2026-34910

UniFi OS Server Command Injection

Ubiquiti / UniFi OS Server · affected before 5.0.8

Severity
CVSS 10.0 · Critical
Confidence
Confirmed
Exploit status
Observed in sensors
EPSS
45.8%
First observed
11 Jun 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-2026-34910 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 Input Validation vulnerability found...

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 Command Injection

A malicious actor with access to the network could exploit an Improper Input Validation vulnerability found in UniFi OS devices to execute a Command Injection.

Ubiquiti Inc Affected
UniFi OS Server
Before 5.0.8
Ubiquiti Inc Affected
UDM
Before 5.1.12
Ubiquiti Inc Affected
UDM-Pro
Before 5.1.12
Ubiquiti Inc Affected
UDM-SE
Before 5.1.12
Ubiquiti Inc Affected
UDM-Pro-Max
Before 5.1.12
Ubiquiti Inc Affected
UDM-Beast
Before 5.1.11
Ubiquiti Inc Affected
EFG
Before 5.1.12
Ubiquiti Inc Affected
UDW
Before 5.1.12
Ubiquiti Inc Affected
UDR
Before 5.1.12
Ubiquiti Inc Affected
UDR7
Before 5.1.12
Ubiquiti Inc Affected
UDR-5G
Before 5.1.12
Ubiquiti Inc Affected
Express 7
Before 5.1.12
Ubiquiti Inc Affected
UNVR
Before 5.1.12
Ubiquiti Inc Affected
UNVR-Pro
Before 5.1.12
Ubiquiti Inc Affected
UNVR-Instant
Before 5.1.12
Ubiquiti Inc Affected
UNVR-G2
Before 5.1.12
Ubiquiti Inc Affected
UNVR-G2-Pro
Before 5.1.12
Ubiquiti Inc Affected
ENVR
Before 5.1.12
Ubiquiti Inc Affected
ENVR-Core
Before 5.1.12
Ubiquiti Inc Affected
UNAS-2
Before 5.1.10
Ubiquiti Inc Affected
UNAS-4
Before 5.1.10
Ubiquiti Inc Affected
UNAS-Pro
Before 5.1.10
Ubiquiti Inc Affected
UNAS-Pro-4
Before 5.1.10
Ubiquiti Inc Affected
UNAS-Pro-8
Before 5.1.10
Ubiquiti Inc Affected
UCKP
Before 5.1.12
Ubiquiti Inc Affected
UCK
Before 5.1.12
Ubiquiti Inc Affected
UCK-Enterprise
Before 5.1.12
Ubiquiti Inc Affected
UCG-Ultra
Before 5.1.12
Ubiquiti Inc Affected
UCG-Max
Before 5.1.12
Ubiquiti Inc Affected
UCG-Fiber
Before 5.1.12
Ubiquiti Inc Affected
UCG-Industrial
Before 5.1.12
Published
22 May 2026
Exploitation Reported
09 Jun 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

nuclei_scanner cisa

CVE References

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 11 Jun 2026

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

Proof of concept available

Nuclei Templates

Recorded 12 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 08:18 UTC
Previdian Sensors 2026-06-11 12:15 UTC
CISA 2026-06-23 00:00 UTC
CVE 2026-06-23 18:11 UTC
All CISA Advisories 2026-06-23 18:20 UTC
The Shadowserver 2026-07-08 00:00 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.

37

Attempts observed

17

Unique attacker IPs

9

Attacker countries

BG · CH · CN · FR · ID · JP · NL · SC · US

20

Sensors observed

CVE-2026-34910 exploitation attempts over the last 91 days

Daily events observed by Previdian sensors

Updated 22 Oct 2026

1
0
0
0
0
0
2
0
0
0
0
0
0
0
0
0
0
0
1
1
3
0
0
0
1
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
7
0
0
0
0
0
0
0
1
1
0
0
1
0
0
0
1
0
0
0
0
0
2
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0
2
0
0
0
0
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1
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1
6
24 Jul 12 Aug 31 Aug 19 Sep 22 Oct

First observed 11 Jun 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
18
16
4

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

Virtual patch status

Previdian virtual patch guidance is available for this CVE.

AWS WAF Cloudflare ModSecurity

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.

Virtual Patch Detail

Compensating WAF rules for this CVE.

Available

Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to Previdian Enterprise users.

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

45.8%

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

Recent mention · The Hacker News

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

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...

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.

gagaltotal/CVE-2026-34910-unifi-poc

github · Created 2026-08-22 11:22:33 UTC · 0 stars · AI assessment 90%

CVE-2026-34910 - CVE-2026-34909 Unifi OS

Boreas37/CVE-2026-34910-PoC

github · Created 2026-08-09 16:58:00 UTC · 2 stars · AI assessment 90%

CVE-2026-34910/34909 — UniFi OS unauth RCE + file read via ..%2f auth bypass (CVSS 10.0, KEV, Mirai ITW)

UniFi OS Server - Command Injection

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

  1. 11:31 UTC

    KEV confirmed by The Hacker News

    Exploitation attested by an external source

  2. 00:00 UTC

    KEV confirmed by The Shadowserver

    Exploitation attested by an external source

  3. 18:20 UTC

    KEV confirmed by All CISA Advisories

    Exploitation attested by an external source

  4. 18:11 UTC

    KEV confirmed by CVE

    Exploitation attested by an external source

  5. 00:00 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  6. 14:21 UTC

    Virtual patch available

    Compensating WAF rule available to block exploitation

  7. 14:21 UTC

    Public PoC available

    Public proof-of-concept code published

  8. 12:15 UTC

    Indicators of compromise added (22)

    Indicators of compromise recorded

  9. 12:15 UTC

    Observed by Previdian sensors

    Evidence-backed exploitation signal

  10. 04:30 UTC

    Nuclei template available

    Scanner coverage available

  11. 08:18 UTC

    Added to Previdian KEV Feed

    High-confidence, third-party attested exploitation

  12. 00:43 UTC

    CVE published

    Vulnerability disclosed publicly

  13. 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.

  • 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-2026-34910

Sample API response
{
  "cve_id": "CVE-2026-34910",
  "confidence": "Confirmed",
  "cvss_score": 10.0,
  "cvss_estimated": false,
  "epss_score": 0.45768,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "attempts": 37, "sensors": 20 }
}