# CVE-2026-74258: bpf: Guard __get_user acesss with access_ok for uprobe_multi data

> Missing access_ok check in Linux kernel BPF uprobe_multi allows unauthorized user-space memory access, potentially leading to privilege escalation or data leaks.

- **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:** 15 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** AZL-96552, BELL-CVE-2026-74258, DEBIAN-CVE-2026-74258, GHSA-pwvf-7f5w-2qr5, UBUNTU-CVE-2026-74258

## What is CVE-2026-74258?

CVE-2026-74258 is a high-severity missing authorization vulnerability in Linux, published on 15 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:

bpf: Guard __get_user acesss with access_ok for uprobe_multi data

As reported by sashiko [1] we need to use access_ok to check the user
space data bounds before we use __get-user to get it.

[1] https://lore.kernel.org/bpf/20260610145235.CB1441F00893@smtp.kernel.org/

## Which versions are affected by CVE-2026-74258?


## How do I fix CVE-2026-74258?

Apply the vendor's patch.

## Is CVE-2026-74258 being exploited?

There is no known exploitation of CVE-2026-74258 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74258 and fix it if it is affected.

What it is: CVE-2026-74258 is a high-severity missing authorization vulnerability in Linux, published on 15 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-2026-74258 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-2026-74258/ (Markdown: https://insights.sbomify.com/CVE-2026-74258/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74258
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74258
- OSV: https://osv.dev/vulnerability/CVE-2026-74258

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74258/
Summaries are generated and may contain mistakes; the official description above is the record.