# CVE-2026-52929: sctp: stream: fully roll back denied add-stream state

> A null-pointer dereference in the Linux kernel SCTP scheduler allows attackers to cause a denial of service by triggering a specific stream addition rollback scenario.

- **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:** 24 Jun 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-90986, BELL-CVE-2026-52929, DEBIAN-CVE-2026-52929, GHSA-5j7v-37xj-7vhm, ROOT-OS-DEBIAN-11-CVE-2026-52929, ROOT-OS-DEBIAN-12-CVE-2026-52929, ROOT-OS-UBUNTU-2204-CVE-2026-52929, ROOT-OS-UBUNTU-2404-CVE-2026-52929, UBUNTU-CVE-2026-52929

## What is CVE-2026-52929?

CVE-2026-52929 is a high-severity vulnerability in Linux kernel, published on 24 Jun 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: stream: fully roll back denied add-stream state

When ADD_OUT_STREAMS is denied, SCTP only shrinks the queued chunks and
then lowers outcnt. That leaves removed stream metadata behind, so a
later re-add can reuse a stale ext and hit a null-pointer dereference in
the scheduler get path.

Fix the rollback by tearing down the removed stream state the same way
other stream resizes do. Unschedule the current scheduler state, drop
the removed stream ext state with sctp_stream_outq_migrate(), and then
reschedule the remaining streams.

This keeps scheduler-private RR/FC/PRIO lists consistent while fully
rolling back denied outgoing stream additions.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-52929?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-52929?

Apply the vendor's patch.

## Is CVE-2026-52929 being exploited?

There is no known exploitation of CVE-2026-52929 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-2026-52929 and fix it if it is affected.

What it is: CVE-2026-52929 is a high-severity vulnerability in Linux kernel, published on 24 Jun 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-2026-52929 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-2026-52929/ (Markdown: https://insights.sbomify.com/CVE-2026-52929/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-52929
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-52929
- OSV: https://osv.dev/vulnerability/CVE-2026-52929

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-52929/
Summaries are generated and may contain mistakes; the official description above is the record.