# CVE-2026-93112: bpf: Require a BPF cpumask for bpf_cpumask_populate()

> A type confusion in the Linux kernel BPF subsystem allows writing to read-only memory, potentially enabling privilege escalation or code execution.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-93112, DEBIAN-CVE-2026-93112, GHSA-8wvc-jp6j-85p4, UBUNTU-CVE-2026-93112

## What is CVE-2026-93112?

CVE-2026-93112 is a high-severity memory corruption 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: Require a BPF cpumask for bpf_cpumask_populate()

bpf_cpumask_populate() writes to its destination with bitmap_copy(), but
the destination is typed as struct cpumask *. That allows the verifier to
accept borrowed cpumask pointers returned by read-only kfuncs, such as
scx_bpf_get_online_cpumask(), as a writable destination.

Make the destination a struct bpf_cpumask * so populate follows the same
ownership rule as the other mutating cpumask kfuncs. Query kfuncs continue
to accept const struct cpumask * inputs.

## Which versions are affected by CVE-2026-93112?


## How do I fix CVE-2026-93112?

Apply the vendor's patch.

## Is CVE-2026-93112 being exploited?

There is no known exploitation of CVE-2026-93112 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93112 and fix it if it is affected.

What it is: CVE-2026-93112 is a high-severity memory corruption 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.
Exploitation: There is no known exploitation of CVE-2026-93112 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-2026-93112/ (Markdown: https://insights.sbomify.com/CVE-2026-93112/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93112
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93112
- OSV: https://osv.dev/vulnerability/CVE-2026-93112

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93112/
Summaries are generated and may contain mistakes; the official description above is the record.