# CVE-2026-72383: sctp: fix addr_wq_timer race in sctp_free_addr_wq()

> A race condition in the Linux kernel SCTP subsystem allows a use-after-free, potentially enabling local attackers to execute code or escalate privileges.

- **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:** 15 Aug 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-96570, BELL-CVE-2026-72383, DEBIAN-CVE-2026-72383, GHSA-8hr4-pprj-6g53, UBUNTU-CVE-2026-72383

## What is CVE-2026-72383?

CVE-2026-72383 is a high-severity use after free vulnerability in Linux, published on 15 Aug 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:

sctp: fix addr_wq_timer race in sctp_free_addr_wq()

sctp_free_addr_wq() previously removed addr_wq_timer using timer_delete()
while holding addr_wq_lock. However, timer_delete() does not guarantee that
a currently running timer handler has completed.

This allows a race with sctp_addr_wq_timeout_handler(), where the handler
may still run after addr_waitq has been freed, acquire addr_wq_lock, and
access freed memory, leading to a use-after-free.

Fix this by calling timer_shutdown_sync() before taking addr_wq_lock.  This
guarantees that any in-flight timer handler has finished and prevents the
timer from being re-armed during teardown, making subsequent cleanup safe.

## Which versions are affected by CVE-2026-72383?


## How do I fix CVE-2026-72383?

Apply the vendor's patch.

## Is CVE-2026-72383 being exploited?

There is no known exploitation of CVE-2026-72383 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72383 and fix it if it is affected.

What it is: CVE-2026-72383 is a high-severity use after free vulnerability in Linux, published on 15 Aug 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-2026-72383 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-2026-72383/ (Markdown: https://insights.sbomify.com/CVE-2026-72383/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72383
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72383
- OSV: https://osv.dev/vulnerability/CVE-2026-72383

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72383/
Summaries are generated and may contain mistakes; the official description above is the record.