CVE-2026-74471 tracing: Check return value of __register_event() in trace_module_add_events()
A use-after-free vulnerability in the Linux kernel tracing subsystem allows attackers to execute arbitrary code or escalate privileges via module loading failures.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-74471?
CVE-2026-74471 is a high-severity use after free vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
tracing: Check return value of __register_event() in trace_module_add_events()
trace_module_add_events() ignores the return value of __register_event() and unconditionally calls __add_event_to_tracers() for each event.
If __register_event() fails (for example, if event_init() fails), the trace_event_call is not added to ftrace_events list, but __add_event_to_tracers() still creates a trace_event_file pointing to it. If module loading subsequently fails and module memory is freed, tracing state retains a stale trace_event_call pointer in trace_event_file, leading to a use-after-free when tracefs or tracing subsystem operations are later executed.
Fix this by checking the return value of __register_event() and only calling __add_event_to_tracers() if event registration succeeded.
Which versions are affected by CVE-2026-74471?
How do I fix CVE-2026-74471?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-74471 being exploited?
There is no known exploitation of CVE-2026-74471 in the wild and no public exploit code.
Sources
Also known as AZL-96021, BELL-CVE-2026-74471, DEBIAN-CVE-2026-74471, GHSA-437h-q69x-6qrx, UBUNTU-CVE-2026-74471.