CVE-2026-74736 net/sched: cls_bpf: reject dev-bound programs bound to a different device
A missing device validation in the Linux kernel cls_bpf classifier allows a local attacker to trigger a kernel panic by attaching a mismatched offloaded program.
- 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-2026-74736?
CVE-2026-74736 is a high-severity denial of service vulnerability in Linux, published on 26 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:
net/sched: cls_bpf: reject dev-bound programs bound to a different device
cls_bpf_prog_from_efd() obtained a SCHED_CLS program via bpf_prog_get_type_dev() but never verified that a device-bound (offloaded) program's bound netdev matches the TC netdev the classifier is being attached to. This let a program loaded with prog_ifindex for device A be attached via cls_bpf + skip_sw to device B; deleting device A then destroyed the program's offload state while it was still attached to device B, triggering a netdevsim WARN (panic with panic_on_warn=1).
Mirror the XDP attach path (net/core/dev.c) and reject the attach with -EINVAL when a dev-bound program's bound device does not match the target device.
Which versions are affected by CVE-2026-74736?
How do I fix CVE-2026-74736?
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-2026-74736 being exploited?
There is no known exploitation of CVE-2026-74736 in the wild and no public exploit code.
Sources
Also known as AZL-97767, BELL-CVE-2026-74736, DEBIAN-CVE-2026-74736, GHSA-3553-97wr-446g, UBUNTU-CVE-2026-74736.