CVE-2026-122164: Windows Kerberos Elevation of Privilege Vulnerability
CVE-2026-122164 is an elevation of privilege vulnerability in Windows Kerberos, rated Important by Microsoft, with a CVSS 3.1 base score of 8 (High). An attacker can exploit it remotely over the network, with high privileges and without user interaction. Microsoft has not reported exploitation in the wild and rates exploitation as unlikely. Microsoft released the fix on 10 November 2026 in the November 2026 Patch Tuesday, delivered through 10 security updates (KB5131291, KB5131085, KB5131096, KB5131090 and more). It affects 28 products in 2 product families (ESU, Windows).
Key facts
- CVE ID
- CVE-2026-122164
- Severity
- High CVSS 8
- Microsoft severity
- Important
- Impact
- Elevation of Privilege
- Exploited in the wild
- No
- Publicly disclosed
- No
- Exploitation likelihood
- Unlikely
- Weakness
- CWE-1390
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- November 2026 Patch Tuesday
- Product families
- ESU, Windows
CVSS score and vector
Microsoft scores CVE-2026-122164 at 8 (temporal 7) using CVSS 3.1. Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C
| Metric | Value |
|---|---|
| Attack vector | Network |
| Attack complexity | High |
| Privileges required | High |
| User interaction | None |
| Scope | Changed |
| Confidentiality impact | High |
| Integrity impact | High |
| Availability impact | High |
| Exploit code maturity | Unproven |
| Remediation level | Official fix |
| Report confidence | Confirmed |
Description
Weak authentication in Windows Kerberos allows an authorized attacker to elevate privileges over a network.
Frequently asked questions (Microsoft)
How could an attacker exploit this vulnerability?
An attacker who controls authentication in a trusted forest could send specially crafted authentication information to the target forest. Successful exploitation could raise the integrity level of the attacker's identity to System, allowing actions otherwise blocked by integrity-level restrictions where existing resource permissions already allow access. This does not grant SYSTEM-account privileges or target-forest administrator membership.
According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability?
Successful exploitation requires an existing trust relationship between the attacker's forest and the target forest, together with resource permissions that already allow the attacker's identity access. The vulnerability bypasses integrity-level restrictions but does not grant otherwise absent resource access permissions.
Affected products (28)
ESU
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| 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 10 Version 22H2 for 32-bit Systems | ||||
| Windows 10 Version 22H2 for ARM64-based Systems | ||||
| Windows 10 Version 22H2 for x64-based Systems |
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 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 2022 | KB5131090 | Security Update | 10.0.20348.5870 | Yes |
| Windows Server 2022 (Server Core installation) | KB5131090 | Security Update | 10.0.20348.5870 | Yes |
| 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 | KB5132061 KB5132043 | Security Update Security Update | 10.0.26100.9974 10.0.26100.9911 | Yes No |
| Windows 11 Version 24H2 for x64-based Systems | KB5132061 KB5132043 | Security Update Security Update | 10.0.26100.9974 10.0.26100.9911 | Yes No |
| Windows 11 Version 25H2 for ARM64-based Systems | KB5132043 | Security Update | 10.0.26200.9911 | No |
| Windows 11 Version 25H2 for x64-based Systems | KB5132043 | Security Update | 10.0.26200.9911 | No |
| 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 |
| Windows Server 2025 | KB5131080 KB5131077 | Security Update Security Update | 10.0.26100.33822 10.0.26100.33730 | Yes No |
| 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 26H1 for ARM64-based Systems | KB5132059 | Security Update | 10.0.28000.3501 | Yes |
| Windows 11 version 26H1 for x64-based Systems | KB5132059 | Security Update | 10.0.28000.3501 | Yes |
Security updates (10)
NIST NVD data
- NVD status
- Awaiting Analysis
- NVD CVSS
- 8 (HIGH)
- NVD weakness
- CWE-1390
- Published to NVD
- NVD last modified
References
Acknowledgments
- yhw
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. |