CVE-2025-54957
Critical CVSS 9.8Published 2025-10-20 ยท last changed 2026-06-17
The fix
Microsoft fixes this in updatesKB5066837, KB5066836, KB5066586, KB5066791, KB5066793, KB5066835, KB5066782, KB5066780. The fixed build differs per Windows version, so the row that matters is the one matching the machine you are looking at.
| Windows version | Fixed in build | Update | Released |
|---|---|---|---|
| Windows 10 for 32-bit Systems | 10.0.10240.21161 | KB5066837 | 2026-09-19 |
| Windows 10 for x64-based Systems | 10.0.10240.21161 | KB5066837 | 2026-09-19 |
| Windows 10 Version 1607 for 32-bit Systems | 10.0.14393.8519 | KB5066836 | 2026-09-19 |
| Windows 10 Version 1607 for x64-based Systems | 10.0.14393.8519 | KB5066836 | 2026-09-19 |
| Windows 10 Version 1809 for 32-bit Systems | 10.0.17763.7919 | KB5066586 | 2026-09-19 |
| Windows 10 Version 1809 for x64-based Systems | 10.0.17763.7919 | KB5066586 | 2026-09-19 |
| Windows 10 Version 21H2 for 32-bit Systems | 10.0.19044.6456 | KB5066791 | 2026-09-19 |
| Windows 10 Version 21H2 for ARM64-based Systems | 10.0.19044.6456 | KB5066791 | 2026-09-19 |
| Windows 10 Version 21H2 for x64-based Systems | 10.0.19044.6456 | KB5066791 | 2026-09-19 |
| Windows 10 Version 22H2 for 32-bit Systems | 10.0.19045.6456 | KB5066791 | 2026-09-19 |
| Windows 10 Version 22H2 for ARM64-based Systems | 10.0.19045.6456 | KB5066791 | 2026-09-19 |
| Windows 10 Version 22H2 for x64-based Systems | 10.0.19045.6456 | KB5066791 | 2026-09-19 |
| Windows 11 Version 22H2 for ARM64-based Systems | 10.0.22621.6060 | KB5066793 | 2026-09-19 |
| Windows 11 Version 22H2 for x64-based Systems | 10.0.22621.6060 | KB5066793 | 2026-09-19 |
| Windows 11 Version 23H2 for ARM64-based Systems | 10.0.22631.6060 | KB5066793 | 2026-09-19 |
| Windows 11 Version 23H2 for x64-based Systems | 10.0.22631.6060 | KB5066793 | 2026-09-19 |
| Windows 11 Version 24H2 for ARM64-based Systems | 10.0.26100.6899 | KB5066835 | 2026-09-19 |
| Windows 11 Version 24H2 for x64-based Systems | 10.0.26100.6899 | KB5066835 | 2026-09-19 |
| Windows 11 Version 25H2 for ARM64-based Systems | 10.0.26200.6899 | KB5066835 | 2026-09-19 |
| Windows 11 Version 25H2 for x64-based Systems | 10.0.26200.6899 | KB5066835 | 2026-09-19 |
| Windows Server 2016 | 10.0.14393.8519 | KB5066836 | 2026-09-19 |
| Windows Server 2016 (Server Core installation) | 10.0.14393.8519 | KB5066836 | 2026-09-19 |
| Windows Server 2019 | 10.0.17763.7919 | KB5066586 | 2026-09-19 |
| Windows Server 2019 (Server Core installation) | 10.0.17763.7919 | KB5066586 | 2026-09-19 |
| Windows Server 2022 | 10.0.20348.4294 | KB5066782 | 2026-09-19 |
| Windows Server 2022, 23H2 Edition (Server Core installation) | 10.0.25398.1913 | KB5066780 | 2026-09-19 |
| Windows Server 2022 (Server Core installation) | 10.0.20348.4294 | KB5066782 | 2026-09-19 |
| Windows Server 2025 | 10.0.26100.6899 | KB5066835 | 2026-09-19 |
| Windows Server 2025 (Server Core installation) | 10.0.26100.6899 | KB5066835 | 2026-09-19 |
Having the KB is not the same as knowing whether a machine has it. Windows updates supersede each other, so the update you installed often covers a fix that shipped in an earlier one. Paste your build into the patch checker and it walks that chain for you.
What it is
An issue was discovered in Dolby UDC 4.5 through 4.13. A crash of the DD+ decoder process can occur when a malformed DD+ bitstream is processed. When Evolution data is processed by evo_priv.c from the DD+ bitstream, the decoder writes that data into a buffer. The length calculation for a write can overflow due to an integer wraparound. This can lead to the allocated buffer being too small, and the out-of-bounds check of the subsequent write to be ineffective, leading to an out-of-bounds write.
Sources
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H