# 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.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** Yes
- **Published:** 26 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** AZL-97767, BELL-CVE-2026-74736, DEBIAN-CVE-2026-74736, GHSA-3553-97wr-446g, UBUNTU-CVE-2026-74736

## 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.

## Is CVE-2026-74736 being exploited?

There is no known exploitation of CVE-2026-74736 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74736 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-74736 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-74736/ (Markdown: https://insights.sbomify.com/CVE-2026-74736/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74736
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74736
- OSV: https://osv.dev/vulnerability/CVE-2026-74736

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74736/
Summaries are generated and may contain mistakes; the official description above is the record.