CVE-2026-85844: Windows Kerberos Elevation of Privilege Vulnerability
CVE-2026-85844 is an elevation of privilege vulnerability in Windows Kerberos, rated Important by Microsoft, with a CVSS 3.1 base score of 9.8 (Critical). An attacker can exploit it remotely over the network, without any privileges and without user interaction. Microsoft has not reported exploitation in the wild and rates exploitation as less likely. Microsoft released the fix on 10 November 2026 in the November 2026 Patch Tuesday, delivered through 12 security updates (KB5131085, KB5131090, KB5131096, KB5131080 and more). It affects 32 products in 2 product families (Windows, ESU).
Key facts
- CVE ID
- CVE-2026-85844
- Severity
- Critical CVSS 9.8
- Microsoft severity
- Important
- Impact
- Elevation of Privilege
- Exploited in the wild
- No
- Publicly disclosed
- No
- Exploitation likelihood
- Less Likely
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- November 2026 Patch Tuesday
- Product families
- Windows, ESU
From the November 2026 Patch Tuesday briefing
Windows Kerberos privilege elevation
This critical Windows and ESU flaw enables elevation of privilege in Kerberos, making it particularly relevant to identity infrastructure. A network attacker needs neither sign-in nor user action. Microsoft rates exploitation less likely. The weakness is CWE-288, authentication bypass using an alternate path or channel. CVSS: 9.8, vector 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.
From the briefing, written by an AI model from PatchaPalooza's data.
CVSS score and vector
Microsoft scores CVE-2026-85844 at 9.8 (temporal 8.5) using CVSS 3.1. Vector: 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
| Metric | Value |
|---|---|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality impact | High |
| Integrity impact | High |
| Availability impact | High |
| Exploit code maturity | Unproven |
| Remediation level | Official fix |
| Report confidence | Confirmed |
Description
Authentication bypass using an alternate path or channel in Windows Kerberos allows an unauthorized attacker to elevate privileges over a network.
Frequently asked questions (Microsoft)
How could an attacker exploit this vulnerability?
An unauthenticated attacker could send specially crafted Kerberos authentication traffic and relay the resulting authentication to an affected domain controller. Successful exploitation could allow the attacker to gain SYSTEM privileges on the domain controller. No user interaction is required.
What privileges could be gained by an attacker who successfully exploited this vulnerability?
An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.
Affected products (32)
Windows
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| Windows 10 Version 1809 for 32-bit Systems | KB5131085 | Security Update | 10.0.17763.9487 | Yes |
| Windows 10 Version 1809 for x64-based Systems | KB5131085 | Security Update | 10.0.17763.9487 | Yes |
| Windows Server 2019 | KB5131085 | Security Update | 10.0.17763.9487 | Yes |
| Windows Server 2019 (Server Core installation) | KB5131085 | Security Update | 10.0.17763.9487 | Yes |
| Windows Server 2022 | KB5131090 | Security Update | 10.0.20348.5870 | Yes |
| Windows Server 2022 (Server Core installation) | KB5131090 | Security Update | 10.0.20348.5870 | Yes |
| Windows 10 Version 21H2 for 32-bit Systems | KB5131096 | Security Update | 10.0.19044.7846 | Yes |
| Windows 10 Version 21H2 for ARM64-based Systems | KB5131096 | Security Update | 10.0.19044.7846 | Yes |
| Windows 10 Version 21H2 for x64-based Systems | KB5131096 | Security Update | 10.0.19044.7846 | Yes |
| Windows Server 2025 (Server Core installation) | KB5131080 KB5131077 | Security Update Security Update | 10.0.26100.33822 10.0.26100.33730 | Yes No |
| Windows 11 Version 25H2 for ARM64-based Systems | KB5132061 KB5132043 | Security Update Security Update | 10.0.26200.9974 10.0.26200.9911 | Yes No |
| Windows 11 Version 25H2 for x64-based Systems | KB5132061 KB5132043 | Security Update Security Update | 10.0.26200.9974 10.0.26200.9911 | Yes No |
| Windows 11 Version 23H2 for ARM64-based Systems | KB5131087 | Security Update | 10.0.22631.7711 | Yes |
| Windows 11 Version 23H2 for x64-based Systems | KB5131087 | Security Update | 10.0.22631.7711 | Yes |
| Windows 11 Version 24H2 for ARM64-based Systems | KB5132043 | Security Update | 10.0.26100.9911 | No |
| Windows 11 Version 24H2 for x64-based Systems | KB5132043 | Security Update | 10.0.26100.9911 | No |
| Windows Server 2025 | KB5131080 KB5131077 | Security Update Security Update | 10.0.26100.33822 10.0.26100.33730 | Yes No |
| Windows 11 version 26H1 for x64-based Systems | KB5132059 | Security Update | 10.0.28000.3501 | Yes |
| Windows 11 Version 26H1 for ARM64-based Systems | KB5132059 | Security Update | 10.0.28000.3501 | Yes |
| Windows 11 Version 26H2 for ARM64-based Systems | KB5132043 | Security Update | 10.0.26300.9911 | No |
| Windows 11 Version 26H2 for x64-based Systems | KB5132043 | Security Update | 10.0.26300.9911 | No |
ESU
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| Windows 10 Version 22H2 for x64-based Systems | ||||
| Windows 10 Version 22H2 for ARM64-based Systems | ||||
| Windows 10 Version 22H2 for 32-bit Systems | ||||
| Windows 10 Version 1607 for 32-bit Systems | KB5131291 | Security Update | 10.0.14393.9688 | Yes |
| Windows 10 Version 1607 for x64-based Systems | KB5131291 | Security Update | 10.0.14393.9688 | Yes |
| Windows Server 2016 | KB5131291 | Security Update | 10.0.14393.9688 | Yes |
| Windows Server 2016 (Server Core installation) | KB5131291 | Security Update | 10.0.14393.9688 | Yes |
| Windows Server 2012 | KB5126835 | Security Update | 6.2.9200.26434 | Yes |
| Windows Server 2012 (Server Core installation) | KB5126835 | Security Update | 6.2.9200.26434 | Yes |
| Windows Server 2012 R2 | KB5126836 | Monthly Rollup | 6.3.9600.23470 | Yes |
| Windows Server 2012 R2 (Server Core installation) | KB5126836 | Monthly Rollup | 6.3.9600.23470 | Yes |
Security updates (12)
- KB5131085 (Security Update)
- KB5131090 (Security Update)
- KB5131096 (Security Update)
- KB5131080 (Security Update)
- KB5131077 (Security Update)
- KB5132061 (Security Update)
- KB5132043 (Security Update)
- KB5131087 (Security Update)
- KB5132059 (Security Update)
- KB5131291 (Security Update)
- KB5126835 (Security Update)
- KB5126836 (Monthly Rollup)
Acknowledgments
- mad31k
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. |