CVE-2026-118737: Remote Procedure Call Runtime Remote Code Execution Vulnerability
CVE-2026-118737 is a remote code execution vulnerability in Remote Procedure Call Runtime, rated Critical by Microsoft, with a CVSS 3.1 base score of 8.1 (High). 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. The EPSS model estimates a 0.71% probability of exploitation activity in the next 30 days, higher than 54% of all scored vulnerabilities. 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-2026-118737
- Severity
- High CVSS 8.1
- Microsoft severity
- Critical
- Impact
- Remote Code Execution
- Exploited in the wild
- No
- Publicly disclosed
- No
- Exploitation likelihood
- Less Likely
- Weakness
- CWE-347
- EPSS
- 0.71% (percentile 54%)
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- November 2026 Patch Tuesday
- Product families
- ESU, Windows
CVSS score and vector
Microsoft scores CVE-2026-118737 at 8.1 (temporal 7.1) using CVSS 3.1. Vector: CVSS:3.1/AV:N/AC:H/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 | High |
| 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
Improper verification of cryptographic signature in Windows Remote Procedure Call Runtime allows an unauthorized attacker to execute code over a network.
Frequently asked questions (Microsoft)
According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability?
Successful exploitation of this vulnerability requires an attacker to win a race condition.
How could an attacker exploit this vulnerability?
An unauthenticated attacker with network access could exploit a timing-dependent authentication weakness involving a pending DNS query to send specially crafted requests to an affected server. Successful exploitation could allow the attacker to execute code on that server without user interaction.
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
- 8.1 (HIGH)
- NVD weakness
- CWE-347
- Published to NVD
- NVD last modified
References
Acknowledgments
- Anonymous
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. |