# CVE-2026-53246: sctp: validate cached peer INIT chunk length in COOKIE_ECHO processing

> An attacker can trigger out-of-bounds reads and memory corruption in the Linux kernel SCTP implementation by sending a malformed COOKIE_ECHO chunk.

- **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:** 25 Jun 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-90624, BELL-CVE-2026-53246, DEBIAN-CVE-2026-53246, GHSA-48jv-x8c6-486c, ROOT-OS-DEBIAN-11-CVE-2026-53246, ROOT-OS-DEBIAN-12-CVE-2026-53246, ROOT-OS-DEBIAN-13-CVE-2026-53246, ROOT-OS-UBUNTU-2204-CVE-2026-53246, ROOT-OS-UBUNTU-2404-CVE-2026-53246, UBUNTU-CVE-2026-53246

## What is CVE-2026-53246?

CVE-2026-53246 is a critical memory corruption vulnerability in Linux kernel, published on 25 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: validate cached peer INIT chunk length in COOKIE_ECHO processing

When a listening SCTP server processes a COOKIE_ECHO chunk, the cached
peer INIT chunk embedded after the cookie is parsed and its parameters
are later walked by sctp_process_init() using sctp_walk_params().

However, the chunk header length of this cached INIT chunk was not
validated against the remaining buffer in the COOKIE_ECHO payload. If
the length field is inflated, the parameter walk can run beyond the
actual received data, leading to out-of-bounds reads and potential
memory corruption during later parameter handling (e.g. STATE_COOKIE
processing and kmemdup() copies).

Add a bounds check in sctp_unpack_cookie() to ensure the cached INIT
chunk length does not exceed the available data in the COOKIE_ECHO
buffer before it is used.

Weakness: CWE-787 (Out-of-bounds Write), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-53246?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-53246?

Apply the vendor's patch.

## Is CVE-2026-53246 being exploited?

There is no known exploitation of CVE-2026-53246 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-2026-53246 and fix it if it is affected.

What it is: CVE-2026-53246 is a critical memory corruption vulnerability in Linux kernel, published on 25 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-2026-53246 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-2026-53246/ (Markdown: https://insights.sbomify.com/CVE-2026-53246/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53246
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53246
- OSV: https://osv.dev/vulnerability/CVE-2026-53246

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53246/
Summaries are generated and may contain mistakes; the official description above is the record.