A heap‑based buffer overflow exists in the Microsoft PostScript Printer Driver that permits an attacker who has legitimate access to a target system to execute arbitrary code over the network. This flaw effectively grants the attacker the privileges of the driver process, allowing malicious code to run with elevated rights. The vulnerability is a classic out‑of‑bounds write (CWE‑122), which can compromise confidentiality, integrity, or availability depending on the payload used.

Microsoft Windows 10 releases 1607, 1809, 21H2, and 22H2, as well as Windows 11 releases 23H2, 24H2, 25H2, 26H2, and 26H1, and the corresponding ARM64 or x86 builds, are impacted. Server editions affected include Windows Server 2012, 2012 R2, 2016, 2019, 2022, and 2025, covering both standard and core installations. All affected machines that have the Microsoft PostScript Printer Driver installed are at risk.

The CVSS score of 8.8 indicates a high severity and the lack of an EPSS score means the current data shows no immediate exploitation trend, yet the flaw remains a powerful attack vector once an authorized attacker gains network access to a vulnerable host. Because the flaw requires an attacker already authorized on the network, it does not allow unauthenticated exploitation but can be leveraged in lateral movement or privilege escalation scenarios. The vulnerability is not listed in the CISA KEV catalog, but the potential impact and high CVSS warrant prompt remediation.