CVE-2026-49166 in Windows
Summary
by MITRE • 07/14/2026
Use after free in Microsoft Printer Drivers allows an authorized attacker to elevate privileges locally.
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Analysis
by VulDB Data Team • 07/14/2026
This vulnerability represents a critical use-after-free condition affecting Microsoft printer drivers that enables local privilege escalation for authenticated attackers. The flaw exists within the print spooler service components that handle driver installations and operations, creating an exploitable memory management error where freed memory blocks are still accessed by subsequent operations. When an attacker with valid user credentials manipulates printer driver installation processes or interacts with specific print queue operations, the system fails to properly validate memory references after deallocation, allowing malicious code execution with elevated privileges. The vulnerability demonstrates characteristics consistent with CWE-416 Use After Free, where program execution continues to reference memory that has been freed by a previous operation. Attackers can leverage this weakness through legitimate user accounts to execute arbitrary code at kernel level, bypassing standard security controls and gaining full system control. The operational impact extends beyond simple privilege escalation as it allows attackers to establish persistent access, escalate further to other systems, or extract sensitive data from the compromised machine. This vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under T1068 Privilege Escalation and T1543 Create or Modify System Process, where adversaries exploit software flaws to gain elevated system access. The flaw affects multiple Windows versions including windows 10, windows server 2016, and windows server 2019, with the vulnerability being particularly concerning due to its requirement of only local authenticated access rather than network-based exploitation. Microsoft has addressed this issue through their regular security updates, requiring system administrators to apply patches promptly to prevent exploitation attempts. Organizations should implement additional controls such as restricting local user privileges, monitoring print spooler service activities, and maintaining updated antivirus signatures that detect known exploitation patterns. The vulnerability highlights the importance of secure coding practices in system-level components and demonstrates how seemingly routine operations like printer driver management can contain critical security flaws. Security teams should monitor for unusual print queue modifications or driver installation attempts as potential indicators of exploitation attempts, while also considering the broader implications of privilege escalation vulnerabilities in Windows operating systems.