CVE-2026-74471

Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source

AV:LAttack vector, local

The bug is reached only via local init_module/finit_module module loading (MODULE_STATE_COMING notifier) and subsequent tracefs/tracing operations on poisoned event files; there is no network, adjacent-wireless, or physical-device input path into trace_module_add_events() or the stale trace_event_file dereferences.

AC:LAttack complexity, low

An attacker can deterministically craft a module whose trace events fail event_init()/__register_event() while __add_event_to_tracers() still runs, then force module-load failure or rmmod to free module memory; no uncontrollable race, rare kernel config, or victim-specific memory layout is required.

PR:LPrivileges required, low

Triggering the UAF requires only local tracefs/tracing access, which tracing_check_open() gates solely with LOCKDOWN_TRACEFS and DAC (no capable() check), commonly granted to tracing-group/Android/ChromeOS diagnostics users; priming stale pointers via init_module uses capable(CAP_SYS_MODULE) but is achievable on permissive dev/container hosts loading attacker modules.

UI:NUser interaction, none

Once tracefs is accessible, the attacker can read/write event enable/format files or invoke tracing helpers that iterate tr->events and dereference the stale trace_event_call without any separate victim user performing mounts, clicks, or configuration changes.

S:UScope, unchanged

The use-after-free corrupts kernel tracing heap/metadata within the same OS security authority and enables local privilege escalation; it does not cross VM, container, IOMMU, or hardware trust boundaries.

C:HConfidentiality impact, high

Stale trace_event_file->event_call pointers reference freed module slab memory; subsequent trace_event_name(), call->class, and reg/unreg callbacks read attacker-influenced reclaimed heap contents, giving an arbitrary kernel memory read primitive typical of UAF bugs.

I:HIntegrity impact, high

Operations such as __ftrace_event_enable_disable() invoke call->class->reg() through the dangling trace_event_call and manipulate event flags/filters on reclaimed objects, providing controllable kernel writes and a standard UAF path to code execution.

A:HAvailability impact, high

Dereferencing freed module-resident trace_event_call structures from tracefs or tracing subsystem operations readily causes kernel oops/panic; even without full exploitation, the UAF reliably threatens system availability and can be retriggered at will.