CVE-2026-90300 bpf: Clear buf on error in __bpf_get_task_stack
A local attacker with BPF privileges can read uninitialized kernel memory via stack trace helpers, potentially leaking sensitive data.
- 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-2026-90300?
CVE-2026-90300 is a vulnerability in Linux, published on 17 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:
bpf: Clear buf on error in __bpf_get_task_stack
Both bpf_get_task_stack and bpf_get_task_stack_sleepable helpers that use __bpf_get_task_stack have buf defined as ARG_PTR_TO_UNINIT_MEM argument and we should initialize the buf on every return path.
Adding missing buf memset for __bpf_get_task_stack fail paths. This provides deterministic buffer contents, which is useful when the buffer is used directly as a map key.
Which versions are affected by CVE-2026-90300?
How do I fix CVE-2026-90300?
Apply the vendor's patch.
Is CVE-2026-90300 being exploited?
There is no known exploitation of CVE-2026-90300 in the wild and no public exploit code.
Sources
Also known as AZL-102008, BELL-CVE-2026-90300, DEBIAN-CVE-2026-90300, GHSA-ghq7-v2f8-82jr, UBUNTU-CVE-2026-90300.