# CVE-2026-46322: tun: free page on build_skb failure in tun_xdp_one()

> A memory leak in the Linux kernel's tun driver allows attackers to exhaust system memory via build_skb failures, causing denial of service.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Jun 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-89678, BELL-CVE-2026-46322, DEBIAN-CVE-2026-46322, GHSA-3r6q-v9jg-jvv4, ROOT-OS-DEBIAN-11-CVE-2026-46322, ROOT-OS-DEBIAN-12-CVE-2026-46322, ROOT-OS-DEBIAN-13-CVE-2026-46322, ROOT-OS-UBUNTU-2204-CVE-2026-46322, ROOT-OS-UBUNTU-2404-CVE-2026-46322, UBUNTU-CVE-2026-46322

## What is CVE-2026-46322?

CVE-2026-46322 is a high-severity denial of service vulnerability in Linux kernel, published on 9 Jun 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:

tun: free page on build_skb failure in tun_xdp_one()

When build_skb() fails in tun_xdp_one(), the function sets ret to
-ENOMEM and jumps to the out label, which returns without freeing the
page that vhost_net_build_xdp() allocated for the frame. As with the
short-frame rejection path, tun_sendmsg() discards the per-buffer error
and still returns total_len, so vhost_tx_batch() takes the success path
and never frees the page. Each build_skb() failure in a batch leaks one
page-frag chunk.

Free the page before taking the error path, matching the put_page() the
other error exits of tun_xdp_one() already perform.

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2026-46322?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46322?

Apply the vendor's patch.

## Is CVE-2026-46322 being exploited?

There is no known exploitation of CVE-2026-46322 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-46322 and fix it if it is affected.

What it is: CVE-2026-46322 is a high-severity denial of service vulnerability in Linux kernel, published on 9 Jun 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-2026-46322 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-46322/ (Markdown: https://insights.sbomify.com/CVE-2026-46322/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46322
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46322
- OSV: https://osv.dev/vulnerability/CVE-2026-46322

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46322/
Summaries are generated and may contain mistakes; the official description above is the record.