# CVE-2026-53313: drm/amd/display: Avoid NULL dereference in dc_dmub_srv error paths

> A NULL pointer dereference in the Linux kernel's AMD display driver can cause a system crash when error logging is triggered.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 26 Jun 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-91326, BELL-CVE-2026-53313, DEBIAN-CVE-2026-53313, GHSA-2885-rcqv-3jp6, ROOT-OS-DEBIAN-12-CVE-2026-53313, ROOT-OS-DEBIAN-13-CVE-2026-53313, ROOT-OS-UBUNTU-2204-CVE-2026-53313, ROOT-OS-UBUNTU-2404-CVE-2026-53313, UBUNTU-CVE-2026-53313

## What is CVE-2026-53313?

CVE-2026-53313 is a medium-severity vulnerability in Linux kernel, published on 26 Jun 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: Avoid NULL dereference in dc_dmub_srv error paths

In dc_dmub_srv_log_diagnostic_data() and
dc_dmub_srv_enable_dpia_trace().

Both functions check:

  if (!dc_dmub_srv || !dc_dmub_srv->dmub)

and then call DC_LOG_ERROR() inside that block.

DC_LOG_ERROR() uses dc_dmub_srv->ctx internally. So if
dc_dmub_srv is NULL, the logging itself can dereference a
NULL pointer and cause a crash.

Fix this by splitting the checks.

First check if dc_dmub_srv is NULL and return immediately.
Then check dc_dmub_srv->dmub and log the error only when
dc_dmub_srv is valid.

Fixes the below:
../display/dc/dc_dmub_srv.c:962 dc_dmub_srv_log_diagnostic_data() error: we previously assumed 'dc_dmub_srv' could be null (see line 961)
../display/dc/dc_dmub_srv.c:1167 dc_dmub_srv_enable_dpia_trace() error: we previously assumed 'dc_dmub_srv' could be null (see line 1166)

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-53313?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-53313?

Apply the vendor's patch.

## Is CVE-2026-53313 being exploited?

There is no known exploitation of CVE-2026-53313 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-2026-53313 and fix it if it is affected.

What it is: CVE-2026-53313 is a medium-severity vulnerability in Linux kernel, published on 26 Jun 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-2026-53313 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-2026-53313/ (Markdown: https://insights.sbomify.com/CVE-2026-53313/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53313
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53313
- OSV: https://osv.dev/vulnerability/CVE-2026-53313

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53313/
Summaries are generated and may contain mistakes; the official description above is the record.