# CVE-2026-64219: drm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async

> A stack buffer overflow in the Linux kernel's AMD display driver allows attackers to execute arbitrary code or escalate privileges via crafted payload lengths.

- **Severity:** High 7.0 (`CVSS:3.1/AV:L/AC:H/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:** 24 Jul 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-64219, DEBIAN-CVE-2026-64219, GHSA-gjfp-5cfr-xp55, ROOT-OS-UBUNTU-2204-CVE-2026-64219, UBUNTU-CVE-2026-64219

## What is CVE-2026-64219?

CVE-2026-64219 is a high-severity memory corruption vulnerability in Linux kernel, published on 24 Jul 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:

drm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async

[Why&How]
dc_process_dmub_aux_transfer_async() copies payload->length bytes into a
16-byte stack buffer (dpaux.data[16]) guarded only by an ASSERT(), which
is a no-op in release builds. If a caller ever passes length > 16 this
results in a stack buffer overflow via memcpy.

Additionally, link_index is used to dereference dc->links[] without
bounds checking against dc->link_count, risking an out-of-bounds access.

Replace the ASSERT with a hard runtime check that returns false when
payload->length exceeds the destination buffer size, and add a bounds
check for link_index before it is used.

(cherry picked from commit ba4caa9fecdf7a38f98c878ad05a8a64148b6881)

Weakness: CWE-674 (Uncontrolled Recursion), CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2026-64219?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64219?

Apply the vendor's patch.

## Is CVE-2026-64219 being exploited?

There is no known exploitation of CVE-2026-64219 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-2026-64219 and fix it if it is affected.

What it is: CVE-2026-64219 is a high-severity memory corruption vulnerability in Linux kernel, published on 24 Jul 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-2026-64219 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-2026-64219/ (Markdown: https://insights.sbomify.com/CVE-2026-64219/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64219
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64219
- OSV: https://osv.dev/vulnerability/CVE-2026-64219

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64219/
Summaries are generated and may contain mistakes; the official description above is the record.