# CVE-2026-98007: bpf: Reject non-scalar bpf_loop iteration counts

> Privileged BPF programs can trigger a kernel panic by passing pointer values to bpf_loop, causing a denial of service.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-104697, BELL-CVE-2026-98007, DEBIAN-CVE-2026-98007, GHSA-mrrf-4w4m-vf8m, UBUNTU-CVE-2026-98007

## What is CVE-2026-98007?

CVE-2026-98007 is a denial of service 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:

bpf: Reject non-scalar bpf_loop iteration counts

bpf_loop() declares its nr_loops argument as ARG_ANYTHING. Privileged
programs may pass pointer values to such arguments, so check_func_arg()
lets a pointer-valued R1 reach the helper-specific checks.

Since commit bb124da69c47 ("bpf: keep track of max number of bpf_loop
callback iterations"), the verifier marks R1 precise and reads its upper
bound to limit callback simulation. Precision backtracking only accepts
scalar registers, so passing a pointer instead triggers the "backtracking
misuse" verifier warning. Kernels with panic_on_warn enabled subsequently
panic.

Introduce ARG_SCALAR for helper arguments that only accept scalar values
and use it for bpf_loop() nr_loops. Generic helper argument validation then
rejects pointers before loop inlining and precision processing.

## Which versions are affected by CVE-2026-98007?


## How do I fix CVE-2026-98007?

Apply the vendor's patch.

## Is CVE-2026-98007 being exploited?

There is no known exploitation of CVE-2026-98007 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98007 and fix it if it is affected.

What it is: CVE-2026-98007 is a denial of service 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.
Exploitation: There is no known exploitation of CVE-2026-98007 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-2026-98007/ (Markdown: https://insights.sbomify.com/CVE-2026-98007/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98007
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98007
- OSV: https://osv.dev/vulnerability/CVE-2026-98007

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98007/
Summaries are generated and may contain mistakes; the official description above is the record.