# CVE-2026-72413: sctp: fix err_chunk memory leaks in INIT handling

> A memory leak in the Linux kernel SCTP implementation allows remote attackers to cause a denial of service by triggering specific INIT handling errors.

- **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:** 15 Aug 2026
- **Updated:** 3 Oct 2026
- **Also known as:** AZL-96123, BELL-CVE-2026-72413, DEBIAN-CVE-2026-72413, GHSA-765x-xm9f-mfm8, UBUNTU-CVE-2026-72413

## What is CVE-2026-72413?

CVE-2026-72413 is a memory corruption 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:

sctp: fix err_chunk memory leaks in INIT handling

When sctp_verify_init() encounters unrecognized parameters, it allocates an
err_chunk to report them. However, this chunk is leaked in several code
paths:

1. In sctp_sf_do_5_1B_init(), if security_sctp_assoc_request() fails after
   sctp_verify_init() has populated err_chunk, the function returns
   immediately without freeing it.

2. In sctp_sf_do_unexpected_init(), the same leak occurs on the
   security_sctp_assoc_request() failure path.

3. In sctp_sf_do_unexpected_init(), on the success path after copying
   unrecognized parameters to the INIT-ACK, the function returns without
   freeing err_chunk, unlike sctp_sf_do_5_1B_init() which properly frees
   it.

Fix all three leaks by adding sctp_chunk_free(err_chunk) calls before
returning in the error paths and on the success path in
sctp_sf_do_unexpected_init().

## Which versions are affected by CVE-2026-72413?


## How do I fix CVE-2026-72413?

Apply the vendor's patch.

## Is CVE-2026-72413 being exploited?

There is no known exploitation of CVE-2026-72413 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72413 and fix it if it is affected.

What it is: CVE-2026-72413 is a memory corruption 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-2026-72413 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-2026-72413/ (Markdown: https://insights.sbomify.com/CVE-2026-72413/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72413
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72413
- OSV: https://osv.dev/vulnerability/CVE-2026-72413

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72413/
Summaries are generated and may contain mistakes; the official description above is the record.