Microsoft has released its November 2025 security updates, addressing an actively exploited zero-day privilege escalation flaw in the Windows Kernel.
The update package contains patches for 63 unique Common Vulnerabilities and Exposures (CVEs), including this critical zero-day identified as CVE-2025-62215, alongside a separate critical vulnerability and several others deemed “more likely to be targeted.” This relatively smaller release follows a record-busting patch rollout in the previous month, which covered 175 vulnerabilities.
Microsoft describes CVE-2025-62215 as a Windows Kernel Elevation of Privilege Vulnerability with a CVSS 3.1 score of 7.0. This flaw, classified under CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization) and CWE-415 (Double Free), allows an attacker who has already gained initial access to a system to escalate their privileges to administrator level. Its attack vector is local, meaning direct access to the system, either physical or remote via services like SSH, is typically required, or it leverages user interaction. According to Satam Narang, a staff research engineer at Tenable, “While we don’t have the full scope regarding exploitation, based on the fact that this is a privilege escalation flaw, it was likely used as part of post-exploitation activity by an attacker.” This vulnerability is one of 11 privilege escalation bugs patched in the Windows Kernel during 2025.
While the total number of patches is lower than the previous month, the presence of an actively exploited zero-day makes this update crucial. As Dark Reading contributing writer Jai Vijayan noted, “However, it’s not one to sleep on: November’s rollout includes fixes for one actively exploited flaw, five that Microsoft rated as more likely to be targeted, and a single critical vulnerability, alongside the usual mix of privilege escalation, remote code execution (RCE), information disclosure, and denial-of-service (DoS) issues.” The update targets various components, reflecting the continuous effort by software vendors to secure complex operating environments against evolving threats.
A “privilege escalation” vulnerability allows an attacker to gain higher access rights than initially authorized, often turning limited user access into full administrative control. A “race condition” occurs when multiple operations attempt to access and modify the same shared resource simultaneously, and the outcome depends on the specific order in which these operations execute, potentially leading to unintended and exploitable states. Timely application of these patches is essential to prevent threat actors from exploiting known weaknesses, especially those already under active attack.
Organizations and individual users are urged to apply these November 2025 security updates promptly to mitigate the risks posed by these vulnerabilities and protect their systems from potential compromise.