CVE-2026-43010 bpf: Reject sleepable kprobe_multi programs at attach time

Medium 5.5 Published 1 May 2026 Updated 4 Jul 2026

A missing validation in the Linux kernel allows sleepable BPF programs to run in atomic contexts, causing a kernel panic and denial of service.

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-2026-43010?

CVE-2026-43010 is a medium-severity denial of service vulnerability in Linux kernel, published on 1 May 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: Reject sleepable kprobe_multi programs at attach time

kprobe.multi programs run in atomic/RCU context and cannot sleep. However, bpf_kprobe_multi_link_attach() did not validate whether the program being attached had the sleepable flag set, allowing sleepable helpers such as bpf_copy_from_user() to be invoked from a non-sleepable context.

This causes a "sleeping function called from invalid context" splat:

BUG: sleeping function called from invalid context at ./include/linux/uaccess.h:169 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1787, name: sudo preempt_count: 1, expected: 0 RCU nest depth: 2, expected: 0

Fix this by rejecting sleepable programs early in bpf_kprobe_multi_link_attach(), before any further processing.

Which versions are affected by CVE-2026-43010?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-43010?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-43010 being exploited?

There is no known exploitation of CVE-2026-43010 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as AZL-85395, BELL-CVE-2026-43010, DEBIAN-CVE-2026-43010, GHSA-vmmg-rqjm-j9p9, ROOT-OS-DEBIAN-12-CVE-2026-43010, ROOT-OS-DEBIAN-13-CVE-2026-43010 and 2 more.