# CVE-2026-80519: ovpn: finish crypto callback cleanup before peer release

> A use-after-free vulnerability in the Linux kernel's ovpn module allows attackers to cause denial of service or execute arbitrary code via improper peer reference handling.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:** 27 Aug 2026
- **Also known as:** BELL-CVE-2026-80519, DEBIAN-CVE-2026-80519, GHSA-4qjp-chcx-vxh6, UBUNTU-CVE-2026-80519

## What is CVE-2026-80519?

CVE-2026-80519 is a critical use after free 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: finish crypto callback cleanup before peer release

Crypto completion callbacks hold both key-slot and peer references. The
peer reference pins the netdev, and dropping the last peer reference can
let netdev unregistration and module removal make progress.

Do not release that peer reference before the callback has finished its
own cleanup. If ovpn_crypto_key_slot_put runs after ovpn_peer_put, it can
schedule an RCU callback backed by module text after ovpn_cleanup
rcu_barrier has already run. The TX error path also freed the remaining
skb after ovpn_peer_put, leaving callback cleanup outside the peer/netdev
lifetime window.

Release the key slot and free any remaining skb first, then drop the peer
reference as the last callback action.

## Which versions are affected by CVE-2026-80519?


## How do I fix CVE-2026-80519?

Apply the vendor's patch.

## Is CVE-2026-80519 being exploited?

There is no known exploitation of CVE-2026-80519 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80519 and fix it if it is affected.

What it is: CVE-2026-80519 is a critical use after free 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-2026-80519 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-2026-80519/ (Markdown: https://insights.sbomify.com/CVE-2026-80519/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80519
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80519
- OSV: https://osv.dev/vulnerability/CVE-2026-80519

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80519/
Summaries are generated and may contain mistakes; the official description above is the record.