# CVE-2026-93137: bpf: Fix use-after-free on mm_struct in bpf_find_vma()

> A use-after-free in the Linux kernel BPF subsystem allows attackers to execute arbitrary code or escalate privileges via a race condition.

- **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:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-102962, BELL-CVE-2026-93137, DEBIAN-CVE-2026-93137, GHSA-45wg-mg8v-jx77, UBUNTU-CVE-2026-93137

## What is CVE-2026-93137?

CVE-2026-93137 is a high-severity use after free 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: Fix use-after-free on mm_struct in bpf_find_vma()

bpf_find_vma() reads task->mm and calls mmap_read_trylock(mm) without
holding a reference on the mm. On a foreign task, a concurrent exit_mm()
can free the mm_struct between the lockless read and the trylock,
resulting in a use-after-free. mm_struct is not SLAB_TYPESAFE_BY_RCU.

For the current task, task->mm is stable. For a foreign task, pin the mm
under task->alloc_lock and release it with mmput_async(), mirroring commit
d8e27d2d22b6 ("bpf: fix mm lifecycle in open-coded task_vma iterator").
Use spin_trylock() instead of get_task_mm() so BPF context does not block
on alloc_lock. Reject irqs-disabled contexts and !CONFIG_MMU on the
foreign-task path because dropping the mm reference is not safe there.

Race:

  CPU0 (BPF program)                  CPU1 (exiting task)
  ============================        ==========================
  bpf_find_vma(foreign_task):
    mm = task->mm
                                      exit_mm():
                                        task->mm = NULL
                                        mmput(mm) -> frees mm_struct
    mmap_read_trylock(mm)
        // UAF on mm

## Which versions are affected by CVE-2026-93137?


## How do I fix CVE-2026-93137?

Apply the vendor's patch.

## Is CVE-2026-93137 being exploited?

There is no known exploitation of CVE-2026-93137 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93137 and fix it if it is affected.

What it is: CVE-2026-93137 is a high-severity use after free 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-2026-93137 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-2026-93137/ (Markdown: https://insights.sbomify.com/CVE-2026-93137/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93137
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93137
- OSV: https://osv.dev/vulnerability/CVE-2026-93137

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93137/
Summaries are generated and may contain mistakes; the official description above is the record.