# CVE-2026-53135: drm/amd/display: Fix NULL deref and buffer over-read in SDP debugfs

> A local attacker can crash the Linux kernel by writing to a debugfs node when a display connector is unbound, causing a null pointer dereference.

- **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:** 25 Jun 2026
- **Updated:** 25 Jun 2026
- **Also known as:** AZL-90785, BELL-CVE-2026-53135, DEBIAN-CVE-2026-53135, GHSA-mmv6-wm63-ppr6, ROOT-OS-DEBIAN-11-CVE-2026-53135, ROOT-OS-DEBIAN-12-CVE-2026-53135, ROOT-OS-UBUNTU-2204-CVE-2026-53135, ROOT-OS-UBUNTU-2404-CVE-2026-53135, UBUNTU-CVE-2026-53135

## What is CVE-2026-53135?

CVE-2026-53135 is a medium-severity vulnerability in Linux kernel, published on 25 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: Fix NULL deref and buffer over-read in SDP debugfs

[Why & How]
dp_sdp_message_debugfs_write() dereferences connector->base.state->crtc
without checking for NULL. A connector can be connected but not bound to
any CRTC (e.g. after hot-plug before the next atomic commit), causing a
kernel crash when writing to the sdp_message debugfs node.

The function also ignores the user-provided size argument and always
passes 36 bytes to copy_from_user(), reading past the user buffer when
size < 36.

Fix both issues by:
- Returning -ENODEV when connector->base.state or state->crtc is NULL
- Clamping write_size to min(size, sizeof(data))

(cherry picked from commit 6ab4c36a522842ff70474a1c0af2e40e50fc8300)

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-53135?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-53135?

Apply the vendor's patch.

## Is CVE-2026-53135 being exploited?

There is no known exploitation of CVE-2026-53135 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-2026-53135 and fix it if it is affected.

What it is: CVE-2026-53135 is a medium-severity vulnerability in Linux kernel, published on 25 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-2026-53135 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-2026-53135/ (Markdown: https://insights.sbomify.com/CVE-2026-53135/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53135
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53135
- OSV: https://osv.dev/vulnerability/CVE-2026-53135

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53135/
Summaries are generated and may contain mistakes; the official description above is the record.