CVE-2026-97919 tracing: Take the reference before publishing the named histogram trigger
A use-after-free in the Linux kernel tracing subsystem allows local attackers with high privileges to execute arbitrary code or escalate privileges.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-97919?
CVE-2026-97919 is an use after free vulnerability in Linux, published on 25 Sep 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: Take the reference before publishing the named histogram trigger
event_hist_trigger_named_init() puts the trigger on the global named_triggers list and only then takes the reference on the trigger it shares its histogram with:
data->ref++;
save_named_trigger(data->named_data->name, data);
ret = event_hist_trigger_init(data->named_data); if (ret < 0) { kfree(data->cmd_ops); data->cmd_ops = &trigger_hist_cmd; }
return ret;
event_hist_trigger_init() fails when alloc_hist_pad() cannot allocate, and nothing takes the trigger back off the list on the way out. event_hist_trigger_parse() frees it, and the next lookup by name reads the freed object:
BUG: KASAN: slab-use-after-free in find_named_trigger+0xac/0xc0 Read of size 8 at addr ffff888009346860 by task init/1 find_named_trigger+0xac/0xc0 hist_register_trigger+0xc1/0xa00 event_hist_trigger_parse+0x3146/0x6af0 event_trigger_write+0xce/0x160 Freed by task 67: kfree+0x154/0x420 trigger_kthread_fn+0xfd/0x160
Do the reference first and publish once it has succeeded, so that nothing which can fail runs after the trigger becomes findable.
Which versions are affected by CVE-2026-97919?
How do I fix CVE-2026-97919?
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-2026-97919 being exploited?
There is no known exploitation of CVE-2026-97919 in the wild and no public exploit code.
Sources
Also known as AZL-104870, BELL-CVE-2026-97919, DEBIAN-CVE-2026-97919, GHSA-6vf7-pxhp-xpjv, UBUNTU-CVE-2026-97919.