Disclosure summary
Heap-based buffer overflow in Reliable Multicast Transport Driver (RMCAST) allows an unauthorized attacker to execute code over an adjacent network.
Source-reported weakness categories
CWE-122, CWE-190
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
Microsoft Security Updates (CVRF) · 2026-Aug
Open original source · Updated Aug 11, 2026
Windows Reliable Multicast Transport Driver (RMCAST) Remote Code Execution Vulnerability
Maximum of vendor-reported product scores; products and fixed builds are associations, not a universal affected-version statement.
Microsoft maximum product score: 8.8
| Vendor | Product / association | Version / bounds |
|---|---|---|
| Microsoft update guide | Windows 10 Version 1809 for 32-bit Systems | (MSRC status code 3) |
| Microsoft update guide | Windows 10 Version 1809 for x64-based Systems | (MSRC status code 3) |
| Microsoft update guide | Windows Server 2019 | (MSRC status code 3) |
| Microsoft update guide | Windows Server 2019 (Server Core installation) | (MSRC status code 3) |
| Microsoft update guide | Windows Server 2022 | (MSRC status code 3) |
| Microsoft update guide | Windows Server 2022 (Server Core installation) | (MSRC status code 3) |
| Microsoft update guide | Windows 10 Version 21H2 for 32-bit Systems | (MSRC status code 3) |
| Microsoft update guide | Windows 10 Version 21H2 for ARM64-based Systems | (MSRC status code 3) |
| Microsoft update guide | Windows 10 Version 21H2 for x64-based Systems | (MSRC status code 3) |
| Microsoft update guide | Windows 10 Version 22H2 for x64-based Systems | (MSRC status code 3) |
| Microsoft update guide | Windows 10 Version 22H2 for ARM64-based Systems | (MSRC status code 3) |
| Microsoft update guide | Windows 10 Version 22H2 for 32-bit Systems | (MSRC status code 3) |
| Microsoft update guide | Windows Server 2025 (Server Core installation) | (MSRC status code 3) |
| Microsoft update guide | Windows 11 Version 25H2 for ARM64-based Systems | (MSRC status code 3) |
| Microsoft update guide | Windows 11 Version 25H2 for x64-based Systems | (MSRC status code 3) |
| Microsoft update guide | Windows 11 Version 23H2 for ARM64-based Systems | (MSRC status code 3) |
| Microsoft update guide | Windows 11 Version 23H2 for x64-based Systems | (MSRC status code 3) |
| Microsoft update guide | Windows 11 Version 24H2 for ARM64-based Systems | (MSRC status code 3) |
| Microsoft update guide | Windows 11 Version 24H2 for x64-based Systems | (MSRC status code 3) |
| Microsoft update guide | Windows Server 2025 | (MSRC status code 3) |
| Microsoft update guide | Windows 11 version 26H1 for x64-based Systems | (MSRC status code 3) |
| Microsoft update guide | Windows 11 Version 26H1 for ARM64-based Systems | (MSRC status code 3) |
| Microsoft update guide | Windows 10 Version 1607 for 32-bit Systems | (MSRC status code 3) |
| Microsoft update guide | Windows 10 Version 1607 for x64-based Systems | (MSRC status code 3) |
| Microsoft update guide | Windows Server 2016 | (MSRC status code 3) |
| Microsoft update guide | Windows Server 2016 (Server Core installation) | (MSRC status code 3) |
| Microsoft update guide | Windows Server 2012 | (MSRC status code 3) |
| Microsoft update guide | Windows Server 2012 (Server Core installation) | (MSRC status code 3) |
| Microsoft update guide | Windows Server 2012 R2 | (MSRC status code 3) |
| Microsoft update guide | Windows Server 2012 R2 (Server Core installation) | (MSRC status code 3) |
Vendor remediation references
- 5120238 · build 10.0.17763.9121 · product IDs 11568, 11569, 11571, 11572
- Vendor guidance · product IDs 11568, 11569, 11571, 11572
- 5120242 · build 10.0.20348.5499 · product IDs 11923, 11924
- Vendor guidance · product IDs 11923, 11924
- 5120242 · product IDs 11923, 11924
- 5120229 · build 10.0.20348.5440 · product IDs 11923, 11924
- Vendor guidance · product IDs 11923, 11924
- 5120249 · build 10.0.19044.7663 · product IDs 11929, 11930, 11931
- Vendor guidance · product IDs 11929, 11930, 11931
- 5120249 · build 10.0.19045.7663 · product IDs 12097, 12098, 12099
- Vendor guidance · product IDs 12097, 12098, 12099
- 5120233 · build 10.0.26100.33296 · product IDs 12437, 12436
- Vendor guidance · product IDs 12437, 12436
- 5120233 · product IDs 12437, 12436
- 5120228 · build 10.0.26100.33222 · product IDs 12437, 12436
- Vendor guidance · product IDs 12437, 12436
- 5120228 · product IDs 12437, 12436
- 5121003 · build 10.0.26200.9168 · product IDs 20437, 20438
- Vendor guidance · product IDs 20437, 20438
- 5120994 · build 10.0.26200.9106 · product IDs 20437, 20438
- Vendor guidance · product IDs 20437, 20438
- 5120240 · build 10.0.22631.7517 · product IDs 12242, 12243
- Vendor guidance · product IDs 12242, 12243
- 5121003 · build 10.0.26100.9168 · product IDs 12389, 12390
- Vendor guidance · product IDs 12389, 12390
- 5120994 · build 10.0.26100.9106 · product IDs 12389, 12390
- Vendor guidance · product IDs 12389, 12390
- 5121000 · build 10.0.28000.2704 · product IDs 20853, 20854
- Vendor guidance · product IDs 20853, 20854
- 5120418 · build 10.0.14393.9418 · product IDs 10852, 10853, 10816, 10855
- Vendor guidance · product IDs 10852, 10853, 10816, 10855
- 5120386 · build 6.2.9200.26280 · product IDs 10378, 10379
- Vendor guidance · product IDs 10378, 10379
- 5120385 · build 6.3.9600.23338 · product IDs 10483, 10543
- Vendor guidance · product IDs 10483, 10543
Original records & references
- NIST NVD record
- CVE Program record
- msrc.microsoft.com — Vendor advisory
PUBLISHED 2026-08-11T03:00:00-04:00
MODIFIED 2026-08-11T03:00:00-04:00
INGESTED 2026-10-08T12:40:35-04:00