CVE-2026-99238

--- CME Mitigation Guidance (2026-11-04) ---
Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure.

The highest-value action is to acquire trace_types_lock before traversing ftrace_trace_arrays in trace_module_record during module loading or unloading: upgrade to the fixed release, which acquire trace_types_lock with a mutex guard before iterating over ftrace_trace_arrays in trace_module_record(), closing concurrent tracefs instance removal during module loading or unloading. Until patched, this is only a concern on Linux systems where local authenticated users can modify tracefs directory structures and trigger module loading or unloading — Non-Linux operating systems are unaffected — so Restrict write permissions to tracefs hierarchy directories, drop CAP_SYS_ADMIN, and restrict dynamic kernel module loading and unloading. As a compensating measure, audit syscalls targeting tracefs directory removal and module loading events, detect anomalous privilege escalation and tracing manipulation using eBPF probes, detect kernel use-after-free memory dereferences with runtime memory error detection, enforce non-executable permissions on kernel heap structures using the NX/XD bit, randomize kernel code locations with KASLR to hinder control-flow redirection, and prevent kernel execution of userspace code during privilege escalation via SMEP. These controls limit blast radius and contain exploitation, but they do not fix the underlying use-after-free race condition defect — apply the upstream patch to fully remediate.

Highest-impact CME: CME-107 Kernel Module Loading Restriction (high)