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Bad Epoll Linux kernel flaw grants root access to unprivileged users

Feeds.4Sysops •IT News • July 4, 2026

A newly disclosed Linux kernel vulnerability named Bad Epoll (CVE-2026-46242) enables unprivileged local users to gain complete root access. The flaw is a use-after-free memory corruption issue located within the epoll subsystem, a core component heavily utilized by modern server applications and network daemons. Affecting Linux kernel versions 6.4 and later, the vulnerability impacts desktops, enterprise servers, cloud workloads, and potentially Android devices. Source

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Critical Bad Epoll Vulnerability Grants Root Access to Unprivileged Users A newly disclosed Linux kernel vulnerability, named Bad Epoll (CVE-2026-46242), allows unprivileged local users to escalate to root privileges on systems running kernel version 6.4 or later. This use-after-free vulnerability resides in the epoll subsystem, which is critical for I/O event notification in Linux. The flaw affects desktops, servers, cloud workloads, and Android devices. A working exploit has been demonstrated with a 99% success rate, highlighting the severity of the issue. The vulnerability was disclosed on July 3, 2026, but a patch has been available since April 24, 2026, and many distributions have yet to implement it. The incident raises concerns about the effectiveness of AI-assisted security tools, as a prior examination by Anthropic's Mythos failed to identify this flaw. Immediate action is required to mitigate potential exploitation. 10 sources 75

Extracted Entities

Bad Epoll Linux kernel flaw grants root access to unprivileged users

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Extracted Entities

CVEs (1)

CWE Weaknesses (2)

MITRE ATT&CK (1)

Platforms (2)

Vulnerabilities (1)