Is CVE-2026-41089 actively exploited?

Yes. Previdian tracks CVE-2026-41089 as a known exploited vulnerability. Confidence is high.

What exploitation activity has Previdian observed?

Previdian has not yet recorded sensor-observed exploitation attempts for CVE-2026-41089. Our sensors continue to monitor for activity targeting this CVE.

Which versions are affected?

CVE-2026-41089 affects Microsoft Windows Server 2012 and 12 other products. Previdian lists 12 version rows; examples include 6.2.9200.0 to < 6.2.9200.26079 and 6.3.9600.0 to < 6.3.9600.23181.

No. CVE-2026-41089 is not currently listed in CISA KEV.

Vulnerability report

Exploited in the wild High confidence Not in CISA KEV

CVE-2026-41089

Q: What is CVE-2026-41089?

CVE-2026-41089 is an unauthenticated Windows Netlogon Remote Code Execution Vulnerability affecting Microsoft Windows Server 2012 and 12 other products. Stack-based buffer overflow in Windows Netlogon allows an unauthorized attacker to execute code over a network.

Q: How should organizations remediate it?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Q: Is it in CISA KEV?

No. CVE-2026-41089 is not currently listed in CISA KEV.

Windows Netlogon Remote Code Execution Vulnerability

Microsoft / Windows Server 2012 · affected before 6.2.9200.26079

Watch CVE-2026-41089 Browse KEV feed

Severity: CVSS 9.8 · Critical
Confidence: High
Exploit status: Exploited in the wild
EPSS: 1.0%
First observed: —
Last observed: —

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-41089 is an unauthenticated Windows Netlogon Remote Code Execution Vulnerability affecting Microsoft Windows Server 2012 and 12 other products. Stack-based buffer overflow in Windows Netlogon allows an...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is high. Also confirmed by third-party sources.

Who is affected?

Microsoft / Windows Server 2012 affected before 6.2.9200.26079.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Stack-based buffer overflow in Windows Netlogon allows an unauthorized attacker to execute code over a network

Stack-based buffer overflow in Windows Netlogon allows an unauthorized attacker to execute code over a network.

Vendor Product Affected Status

Microsoft Affected

Windows Server 2012

Before 6.2.9200.26079

Affected

Microsoft Affected

Windows Server 2012 (Server Core installation)

Before 6.2.9200.26079

Affected

Microsoft Affected

Windows Server 2012 R2

Before 6.3.9600.23181

Affected

Microsoft Affected

Windows Server 2012 R2 (Server Core installation)

Before 6.3.9600.23181

Affected

Microsoft Affected

Windows Server 2016

Before 10.0.14393.9140

Affected

Microsoft Affected

Windows Server 2016 (Server Core installation)

Before 10.0.14393.9140

Affected

Microsoft Affected

Windows Server 2019

Before 10.0.17763.8755

Affected

Microsoft Affected

Windows Server 2019 (Server Core installation)

Before 10.0.17763.8755

Affected

Microsoft Affected

Windows Server 2022

Before 10.0.20348.5139

Affected

Microsoft Affected

Windows Server 2022, 23H2 Edition (Server Core installation)

Before 10.0.25398.2330

Affected

Microsoft Affected

Windows Server 2025

Before 10.0.26100.32860

Affected

Microsoft Affected

Windows Server 2025 (Server Core installation)

Before 10.0.26100.32860

Affected

View vendor advisory

Published: 12 May 2026
Exploitation Reported: 02 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-2026-41089
Windows Netlogon Remote Code Execution Vulnerability msrc.microsoft.com · Vendor Advisory https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-41089

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

Previdian

Recorded 02 Jun 2026

A trusted third party reported exploitation.

Proof of concept available

GitHub

Recorded 11 Sep 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
CERT-EU First	2026-05-13 15:21 UTC
Previdian	2026-06-02 11:06 UTC
The Shadowserver	2026-06-02 17:21 UTC

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: 0; 0; 0

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

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

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

Learn about virtual patches →

No detection artifacts or sensor request patterns are available for this CVE yet.

Check back as sensor telemetry and scanner integrations are updated.

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

9.8 Critical

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

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

EPSS

1.0%

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

Weaknesses

Stack-based Buffer Overflow CWE-121

Potential Proof of Concepts

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

1posix/CVE-2026-41089-PoC

github · Created 2026-09-26 16:16:08 UTC · 0 stars · AI assessment 90%

CVE-2026-41089 LongLogon: pre-auth CLDAP (UDP/389) stack buffer overflow crasher for unpatched Windows Server 2025 Netlogon (lsass 0xc0000409). Stdlib-only Python PoC + lab write-up.

1posix/CVE-2026-41089-POC

github · Created 2026-09-26 16:16:08 UTC · 0 stars · AI assessment 90%

CVE-2026-41089 LongLogon: pre-auth CLDAP (UDP/389) stack buffer overflow crasher for unpatched Windows Server 2025 Netlogon (lsass 0xc0000409). Stdlib-only Python PoC + lab write-up.

SyntaxMethod/CVE-2026-41089-Netlogon-RCE-PoC

github · Created 2026-09-11 10:34:35 UTC · 0 stars · AI assessment 85%

Description: Unauthenticated Netlogon RCE vulnerability scanner & PoC research for CVE-2026-41089 (CVSS 9.8). Integrated module for AI Security Tool.

Timeline

From disclosure to observed exploitation

11 Sep 2026
10:34 UTC

Public PoC available

Public proof-of-concept code published
02 Jun 2026
17:21 UTC

KEV confirmed by The Shadowserver

Exploitation attested by an external source
02 Jun 2026
11:06 UTC

Added to Previdian KEV Feed

High-confidence, third-party attested exploitation
13 May 2026
15:21 UTC

Added to Previdian KEV Feed

High-confidence, third-party attested exploitation
12 May 2026
16:58 UTC

CVE published

Vulnerability disclosed publicly
16 Apr 2026
19:12 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.

Start 14-day Pro trial Read API docs

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-2026-41089

Sample API response

{
  "cve_id": "CVE-2026-41089",
  "confidence": "High",
  "cvss_score": 9.8,
  "cvss_estimated": false,
  "epss_score": 0.00974,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}

CVE-2026-41089

Stack-based buffer overflow in Windows Netlogon allows an unauthorized attacker to execute code over a network

Tags

CVE References

Exploited in the wild

Proof of concept available

Known exploited vulnerability sources

Observed signals

Scanner coverage

Virtual patch status

Weaknesses

Potential Proof of Concepts

Public PoC available

KEV confirmed by The Shadowserver

Added to Previdian KEV Feed

Added to Previdian KEV Feed

CVE published

CVE ID reserved

Automate this intelligence