# CVE-2026-46330: Revert "net/smc: Introduce TCP ULP support"

> A use-after-free vulnerability in the Linux kernel's SMC TCP ULP support allows attackers to cause system instability or execute code.

- **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:** 9 Jun 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-89696, BELL-CVE-2026-46330, DEBIAN-CVE-2026-46330, GHSA-fm5x-69c3-7mfj, ROOT-OS-DEBIAN-12-CVE-2026-46330, ROOT-OS-DEBIAN-13-CVE-2026-46330, ROOT-OS-UBUNTU-2404-CVE-2026-46330, UBUNTU-CVE-2026-46330

## What is CVE-2026-46330?

CVE-2026-46330 is a high-severity use after free 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:

Revert "net/smc: Introduce TCP ULP support"

This reverts commit d7cd421da9da2cc7b4d25b8537f66db5c8331c40.

As reported by Al Viro, the TCP ULP support for SMC is fundamentally
broken. The implementation attempts to convert an active TCP socket
into an SMC socket by modifying the underlying `struct file`, dentry,
and inode in-place, which violates core VFS invariants that assume
these structures are immutable for an open file, creating a risk of
use after free errors and general system instability.

Given the severity of this design flaw and the fact that cleaner
alternatives (e.g., LD_PRELOAD, BPF) exist for legacy application
transparency, the correct course of action is to remove this feature
entirely.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-46330?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46330?

Apply the vendor's patch.

## Is CVE-2026-46330 being exploited?

There is no known exploitation of CVE-2026-46330 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-2026-46330 and fix it if it is affected.

What it is: CVE-2026-46330 is a high-severity use after free 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-2026-46330 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-2026-46330/ (Markdown: https://insights.sbomify.com/CVE-2026-46330/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46330
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46330
- OSV: https://osv.dev/vulnerability/CVE-2026-46330

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46330/
Summaries are generated and may contain mistakes; the official description above is the record.