Heap overflow in Windows RPC Runtime allows local privilege escalation
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Privilege escalation
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Microsoft. Impact type from Microsoft.
Summary
Microsoft Windows 11 versions 23H2, 24H2, 25H2 and 26H1 contain this flaw in the RPC Runtime. A heap-based buffer overflow (CWE-122) lets an authorized local attacker with low privileges gain elevated privileges on the system.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
Heap-based buffer overflow in RPC Runtime allows an authorized attacker to elevate privileges locally.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Microsoft | Windows 11 version 23H2 | 10.0.22631.0 to before 10.0.22631.7582 | 10.0.22631.7582 | Patch available | CNA |
| Microsoft | Windows 11 Version 23H2 | 10.0.22631.0 to before 10.0.22631.7582 | 10.0.22631.7582 | Patch available | CNA |
| Microsoft | Windows 11 Version 24H2 | 10.0.26100.0 to before 10.0.26100.9445 | 10.0.26100.9445 | Patch available | CNA |
| Microsoft | Windows 11 Version 25H2 | 10.0.26200.0 to before 10.0.26200.9445 | 10.0.26200.9445 | Patch available | CNA |
| Microsoft | Windows 11 version 26H1 | 10.0.28000.0 to before 10.0.28000.2954 | 10.0.28000.2954 | Patch available | CNA |
- Windows 11 version 23H2 VendorMicrosoft Affected 10.0.22631.0 to before 10.0.22631.7582 Fixed in 10.0.22631.7582 Patch available CNA
- Windows 11 Version 23H2 VendorMicrosoft Affected 10.0.22631.0 to before 10.0.22631.7582 Fixed in 10.0.22631.7582 Patch available CNA
- Windows 11 Version 24H2 VendorMicrosoft Affected 10.0.26100.0 to before 10.0.26100.9445 Fixed in 10.0.26100.9445 Patch available CNA
- Windows 11 Version 25H2 VendorMicrosoft Affected 10.0.26200.0 to before 10.0.26200.9445 Fixed in 10.0.26200.9445 Patch available CNA
- Windows 11 version 26H1 VendorMicrosoft Affected 10.0.28000.0 to before 10.0.28000.2954 Fixed in 10.0.28000.2954 Patch available CNA
CPE configurations NVD · 8
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:* | before 10.0.22631.7652 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:* | before 10.0.22631.7652 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:* | before 10.0.26100.9711 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:* | before 10.0.26100.9711 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:* | before 10.0.26200.9711 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:* | before 10.0.26200.9711 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:* | before 10.0.28000.3231 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:* | before 10.0.28000.3231 | Vulnerable | Microsoft |
- cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:* Versions before 10.0.22631.7652 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:* Versions before 10.0.22631.7652 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:* Versions before 10.0.26100.9711 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:* Versions before 10.0.26100.9711 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:* Versions before 10.0.26200.9711 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:* Versions before 10.0.26200.9711 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:* Versions before 10.0.28000.3231 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:* Versions before 10.0.28000.3231 Vulnerable ·Microsoft
Remediation
Windows 11 version 23H2 is fixed in 10.0.22631.7582 (KB5122880), version 24H2 in 10.0.26100.9445 (KB5124008), version 25H2 in 10.0.26200.9445 (KB5124008), and version 26H1 in 10.0.28000.2954 (KB5124012).
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Microsoft 3 updates
- Security Update
- Windows 11 Version 26H1 for ARM64-based Systems 10.0.28000.2954
- Windows 11 version 26H1 for x64-based Systems 10.0.28000.2954
- Security Update
- Windows 11 Version 24H2 for ARM64-based Systems 10.0.26100.9445
- Windows 11 Version 24H2 for x64-based Systems 10.0.26100.9445
- Windows 11 Version 25H2 for ARM64-based Systems 10.0.26200.9445
- Windows 11 Version 25H2 for x64-based Systems 10.0.26200.9445
- Security Update
- Windows 11 Version 23H2 for ARM64-based Systems 10.0.22631.7582
- Windows 11 Version 23H2 for x64-based Systems 10.0.22631.7582
Vendor assessments
Microsoft
Microsoft's page for this CVE →
- Impact
- Elevation of Privilege
- Exploited
- No
- Publicly disclosed
- No
- Exploitability
- Exploitation Less Likely
Timeline
- 2026-10-13 Threatist record created from CVE-2026-83518
- 2026-10-13 Alias added: GHSA-jr84-qg44-hh67
- 2026-10-13 CISA SSVC decision points changed
- 2026-10-14 Priority changed: MEDIUM → LOW
- 2026-10-16 Fix available: KB5122880, KB5124008, KB5124012 · Microsoft
References
More Microsoft Windows 11 23h2 vulnerabilities
- TI-2026-26194 Windows Internet Key Exchange (IKE) Service Extensions Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
- TI-2026-73128 Windows Shell Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 8.8
- TI-2026-17367 MSHTML Framework Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 8.8
- TI-2026-17364 Windows Shell Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 8.8
- TI-2025-24062 Windows SMB Client Elevation of Privilege Vulnerability KEVCVSS 3.1HIGH 8.8
- TI-2025-24042 Internet Shortcut Files Remote Code Execution Vulnerability KEVCVSS 3.1HIGH 8.8
Sources
- CVE-2026-83518 · CVE Program
- CVE-2026-83518 · NVD
- FIRST EPSS
- GHSA-jr84-qg44-hh67 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-83518 · Microsoft Security Update Guide
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences