# CVE-2026-74750: ovpn: defer key slot crypto freeing to workqueue

> A race condition in the Linux kernel's ovpn module allows unsafe memory freeing, potentially causing a system crash or denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 26 Aug 2026
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2026-74750, DEBIAN-CVE-2026-74750, GHSA-2495-48wf-cqx2, UBUNTU-CVE-2026-74750

## What is CVE-2026-74750?

CVE-2026-74750 is a high-severity vulnerability in Linux, published on 26 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

ovpn: defer key slot crypto freeing to workqueue

Key slots are released through a kref and the existing release path
frees the AEAD transforms from an RCU callback. That is not safe for all
crypto implementations: crypto_free_aead can sleep, for example when an
async or hardware implementation has teardown work to complete.

Use queue_rcu_work for key-slot release. This keeps the RCU grace period
needed by lockless key-slot readers, but runs the actual crypto teardown
from workqueue context where sleeping is allowed. Once the rcu_work
callback runs, pre-existing RCU readers are gone, and the final kref put
already proves that no transform user remains, so the worker can release
the AEAD transforms and free the slot directly.

The previous patch drains ovpn_wq during module exit, so queued key-slot
teardown work cannot outlive module text.

## Which versions are affected by CVE-2026-74750?


## How do I fix CVE-2026-74750?

Apply the vendor's patch.

## Is CVE-2026-74750 being exploited?

There is no known exploitation of CVE-2026-74750 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74750 and fix it if it is affected.

What it is: CVE-2026-74750 is a high-severity vulnerability in Linux, published on 26 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-74750 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-2026-74750/ (Markdown: https://insights.sbomify.com/CVE-2026-74750/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74750
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74750
- OSV: https://osv.dev/vulnerability/CVE-2026-74750

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74750/
Summaries are generated and may contain mistakes; the official description above is the record.