# CVE-2026-46263: drm/amd/display: Fix out-of-bounds stream encoder index v3

> An out-of-bounds read in the AMD display driver allows attackers to potentially execute code or crash the system via crafted inputs.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/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:** 3 Jun 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-46263, DEBIAN-CVE-2026-46263, GHSA-8h36-wfww-p7v6, UBUNTU-CVE-2026-46263

## What is CVE-2026-46263?

CVE-2026-46263 is a high-severity memory corruption vulnerability in Linux kernel, published on 3 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 out-of-bounds stream encoder index v3

eng_id can be negative and that stream_enc_regs[]
can be indexed out of bounds.

eng_id is used directly as an index into stream_enc_regs[], which has
only 5 entries. When eng_id is 5 (ENGINE_ID_DIGF) or negative, this can
access memory past the end of the array.

Add a bounds check using ARRAY_SIZE() before using eng_id as an index.
The unsigned cast also rejects negative values.

This avoids out-of-bounds access.

Fixes the below smatch error:
dcn*_resource.c: stream_encoder_create() may index
stream_enc_regs[eng_id] out of bounds (size 5).

drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn351/dcn351_resource.c
    1246 static struct stream_encoder *dcn35_stream_encoder_create(
    1247         enum engine_id eng_id,
    1248         struct dc_context *ctx)
    1249 {

    ...

    1255
    1256         /* Mapping of VPG, AFMT, DME register blocks to DIO block instance */
    1257         if (eng_id <= ENGINE_ID_DIGF) {

ENGINE_ID_DIGF is 5.  should <= be <?

Unrelated but, ugh, why is Smatch saying that "eng_id" can be negative?
end_id is type signed long, but there are checks in the caller which prevent it from being negative.

    1258                 vpg_inst = eng_id;
    1259                 afmt_inst = eng_id;
    1260         } else
    1261                 return NULL;
    1262

    ...

    1281
    1282         dcn35_dio_stream_encoder_construct(enc1, ctx, ctx->dc_bios,
    1283                                         eng_id, vpg, afmt,
--> 1284                                         &stream_enc_regs[eng_id],
                                                  ^^^^^^^^^^^^^^^^^^^^^^^ This stream_enc_regs[] array has 5 elements so we are one element beyond the end of the array.

    ...

    1287         return &enc1->base;
    1288 }

v2: use explicit bounds check as suggested by Roman/Dan; avoid unsigned int cast

v3: The compiler already knows how to compare the two values, so the
    cast (int) is not needed. (Roman)

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-46263?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46263?

Apply the vendor's patch.

## Is CVE-2026-46263 being exploited?

There is no known exploitation of CVE-2026-46263 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-2026-46263 and fix it if it is affected.

What it is: CVE-2026-46263 is a high-severity memory corruption vulnerability in Linux kernel, published on 3 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-2026-46263 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-2026-46263/ (Markdown: https://insights.sbomify.com/CVE-2026-46263/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46263
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46263
- OSV: https://osv.dev/vulnerability/CVE-2026-46263

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46263/
Summaries are generated and may contain mistakes; the official description above is the record.