Heap-based buffer overflow occurs in the Windows Network File System, permitting code execution on the target system. The vulnerability enables an attacker to run arbitrary code with the privileges of the SMB service process, which can lead to further privilege escalation. The weakness involves improper handling of heap allocations, identified as CWE‑122.

Microsoft Windows 10 releases 1607, 1809, 21H2, 22H2; Windows 11 releases 23H2, 24H2, 25H2, 26H2, 23H2 (arm64), 26H1; and Windows Server 2012, 2012 R2, 2016, 2019, 2022, 2025 across both server and core installations are impacted. The CPE list confirms these platforms, and no specific sub‑versions are listed, so all listed editions are vulnerable until patched.

With a CVSS score of 7.8 the vulnerability is considered high severity. The EPSS score is not available, but the lack of public exploitation information and its absence from the CISA KEV catalog suggest a moderate likelihood of real‑world attacks. Based on the description, it is inferred that the attacker must first acquire authorized access to the affected SMB share to trigger the heap corruption, and that the resulting code execution would run with the privileges of the SMB service process, potentially allowing further privilege escalation on the host.