# CVE-2026-68161: sctp: close UDP tunnel sockets during netns teardown

> Attackers can cause a denial of service by tearing down network namespaces while SCTP UDP tunnel sockets remain active, requiring specific sysctl configuration.

- **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:** 10 Aug 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-94950, BELL-CVE-2026-68161, DEBIAN-CVE-2026-68161, GHSA-9g3f-gj9q-hqjj, UBUNTU-CVE-2026-68161

## What is CVE-2026-68161?

CVE-2026-68161 is a critical denial of service vulnerability in Linux, published on 10 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:

sctp: close UDP tunnel sockets during netns teardown

proc_sctp_do_udp_port() starts per-net SCTP UDP tunneling sockets when
net.sctp.udp_port is set, and stops/restarts them when the sysctl value
changes. The netns exit path does not stop these sockets, so a namespace
can be torn down while its SCTP UDP tunnel sockets are still installed.

Close the UDP tunnel sockets from sctp_ctrlsock_exit() after unregistering
the per-net sysctl table. This prevents new sysctl writes from racing in
while the sockets are being released, and closes the sockets before the
control socket is destroyed.

Weakness: CWE-404 (Improper Resource Shutdown or Release)

## Which versions are affected by CVE-2026-68161?


## How do I fix CVE-2026-68161?

Apply the vendor's patch.

## Is CVE-2026-68161 being exploited?

There is no known exploitation of CVE-2026-68161 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68161 and fix it if it is affected.

What it is: CVE-2026-68161 is a critical denial of service vulnerability in Linux, published on 10 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-2026-68161 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-2026-68161/ (Markdown: https://insights.sbomify.com/CVE-2026-68161/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68161
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68161
- OSV: https://osv.dev/vulnerability/CVE-2026-68161

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68161/
Summaries are generated and may contain mistakes; the official description above is the record.