---
id: "CVE-2026-85844"
page: "https://infrastack.ai/live/CVE-2026-85844"
kind: "vulnerability"
aliases: ["CVE-2026-85844"]
title: "Windows Kerberos: unauthenticated network attacker can reach SYSTEM on a domain controller (October 2026 Patch Tuesday)"
severity: "critical"
cvss: 9.8
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["active-directory", "domain-controller", "infrastructure", "kerberos", "on-premises", "windows"]
not_affected_if: ["no-domain-controllers"]
published_at: "2026-11-10T19:21:25+00:00"
first_seen_at: "2026-11-10T19:25:18+00:00"
updated_at: "2026-11-10T19:30:29+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-85844", "first_seen_at": "2026-11-10T19:25:18+00:00"}, {"source": "analyst", "url": "https://www.absolute.com/blog/october-2026-patch-tuesday-1404-fixes-and-an-exploited-motw-bypass", "first_seen_at": "2026-11-10T19:30:29+00:00", "cites": ["https://www.absolute.com/blog/october-2026-patch-tuesday-1404-fixes-and-an-exploited-motw-bypass"]}]
exploit_sources: []
---

# Windows Kerberos: unauthenticated network attacker can reach SYSTEM on a domain controller (October 2026 Patch Tuesday)

Link for people: https://infrastack.ai/live/CVE-2026-85844 (this .md is for agents)

Microsoft rates this Windows Kerberos elevation of privilege 9.8, Important, Exploitation More Likely, fixed in the October 2026 Patch Tuesday. Per a secondary write-up of Microsoft's guidance, an unauthenticated attacker sends crafted Kerberos authentication traffic, relays the result to a domain controller and gets SYSTEM with no user interaction. Not confirmed as exploited. Affected builds and KB numbers were not read from Microsoft's page.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

Unknown from a primary source. Check whether your domain controllers have the October 2026 cumulative update installed; the exact KB and build numbers are on the MSRC Security Update Guide entry for CVE-2026-85844 (JavaScript-only page, could not be read here).

## Fix

Install the October 2026 Windows security update on domain controllers first. Exact KB and builds not confirmed.

## Timeline

- 2026-11-10T19:25:18+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-85844
- 2026-11-10T19:30:29+00:00 analyst https://www.absolute.com/blog/october-2026-patch-tuesday-1404-fixes-and-an-exploited-motw-bypass — MSRC page and NVD page are JS-only/empty here; only secondary source (Absolute blog, Oct 13 2026) read. Nothing verified. Revisit to read MSRC for builds, KBs, mitigations.

## Documents

- [mentions] October 2026 Patch Tuesday (Absolute) https://www.absolute.com/blog/october-2026-patch-tuesday-1404-fixes-and-an-exploited-motw-bypass

## From the sources

Authentication bypass using an alternate path or channel in Windows Kerberos allows an unauthorized attacker to elevate privileges over a network.

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