# CVE-2026-72242: selinux: avoid sk_socket dereference in selinux_sctp_bind_connect()

> A null pointer dereference in the Linux kernel SCTP SELinux hook can cause a system crash when triggered via specific network packets.

- **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:** 15 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** BELL-CVE-2026-72242, DEBIAN-CVE-2026-72242, GHSA-v4p9-3h3v-9gpm, UBUNTU-CVE-2026-72242

## What is CVE-2026-72242?

CVE-2026-72242 is a high-severity vulnerability in Linux, published on 15 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:

selinux: avoid sk_socket dereference in selinux_sctp_bind_connect()

selinux_sctp_bind_connect() dereferences sk->sk_socket to pass a
struct socket * to selinux_socket_bind() and
selinux_socket_connect_helper().  However, when the hook is invoked
from the ASCONF softirq path (sctp_process_asconf), there is no file
reference guaranteeing that sk->sk_socket is non-NULL.  The setsockopt
callers (bindx, connectx, set_primary, sendmsg connect) hold a file
reference and are not affected.

Both selinux_socket_bind() and selinux_socket_connect_helper()
immediately resolve sock->sk, never using the struct socket * for
anything else.  Refactor the inner logic into helpers that take a
struct sock * directly so that selinux_sctp_bind_connect() never needs
to touch sk->sk_socket at all.

## Which versions are affected by CVE-2026-72242?


## How do I fix CVE-2026-72242?

Apply the vendor's patch.

## Is CVE-2026-72242 being exploited?

There is no known exploitation of CVE-2026-72242 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72242 and fix it if it is affected.

What it is: CVE-2026-72242 is a high-severity vulnerability in Linux, published on 15 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-2026-72242 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-2026-72242/ (Markdown: https://insights.sbomify.com/CVE-2026-72242/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72242
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72242
- OSV: https://osv.dev/vulnerability/CVE-2026-72242

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72242/
Summaries are generated and may contain mistakes; the official description above is the record.