# CVE-2026-98846: sctp: check RCV_SHUTDOWN after the sendmsg connect wait

> A use-after-free vulnerability in the Linux kernel SCTP implementation allows attackers to cause denial of service or potentially execute code via crafted network packets.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Oct 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-109110, BELL-CVE-2026-98846, DEBIAN-CVE-2026-98846, GHSA-gghw-9hqp-85hc, UBUNTU-CVE-2026-98846

## What is CVE-2026-98846?

CVE-2026-98846 is an use after free vulnerability in Linux, published on 18 Oct 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: check RCV_SHUTDOWN after the sendmsg connect wait

sctp_wait_for_connect() drops the socket lock while it sleeps. An
out-of-the-blue ABORT can then be processed from the socket backlog and
unlink the association. If a concurrent shutdown(fd, SHUT_RD) sets
RCV_SHUTDOWN, the waiter breaks with err == 0 before checking
asoc->base.dead. Its final sctp_association_put() can then free the
association, leaving sctp_sendmsg_to_asoc() to continue with a dangling
pointer.

Check RCV_SHUTDOWN along with the wait error in sctp_sendmsg_to_asoc()
before using the association again. The check only accesses the socket,
so it needs no additional association reference. Return the existing
-ESRCH so that sctp_sendmsg() skips freeing a new association that may
already have been destroyed.

Keep sctp_wait_for_connect() unchanged to preserve its behavior for the
connect() caller.

## Which versions are affected by CVE-2026-98846?


## How do I fix CVE-2026-98846?

Apply the vendor's patch.

## Is CVE-2026-98846 being exploited?

There is no known exploitation of CVE-2026-98846 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98846 and fix it if it is affected.

What it is: CVE-2026-98846 is an use after free vulnerability in Linux, published on 18 Oct 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-2026-98846 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-2026-98846/ (Markdown: https://insights.sbomify.com/CVE-2026-98846/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98846
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98846
- OSV: https://osv.dev/vulnerability/CVE-2026-98846

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98846/
Summaries are generated and may contain mistakes; the official description above is the record.