CVE-2026-43499
Linux · kernel
A use-after-free vulnerability in the Linux kernel's rtmutex component during proxy-lock rollback can lead to privilege escalation.
Executive summary
A high-severity use-after-free vulnerability in the Linux kernel's real-time mutex subsystem could allow a local attacker to gain elevated privileges.
Vulnerability
During a proxy-lock rollback in rt_mutex_start_proxy_lock(), the kernel incorrectly handles task pointers. This results in a use-after-free condition where a reference to a task is used after it has been improperly managed.
Business impact
The CVSS score of 7.8 underscores the severity of this vulnerability. By exploiting this flaw, a local attacker could potentially achieve privilege escalation, compromising the entire system.
Remediation
Immediate Action: Update the Linux kernel to a patched version that correctly utilizes waiter::task in remove_waiter().
Proactive Monitoring: Monitor for suspicious local processes attempting to interact with futex or real-time mutex operations.
Compensating Controls: Restrict access to local system resources and implement kernel hardening measures to mitigate potential privilege escalation attempts.
Exploitation status
Public Exploit Available: false
Analyst recommendation
Given the potential for privilege escalation, this patch is of high importance. Administrators must ensure that the kernel is updated to a non-vulnerable version as soon as possible.