# CVE-2026-74320: fbdev: sm501fb: Fix buffer errors in OF binding code

> A use-after-free and buffer overrun in the Linux kernel sm501fb driver allows local attackers to execute code or cause a system crash.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** BELL-CVE-2026-74320, DEBIAN-CVE-2026-74320, GHSA-cprm-m4x6-j7h5, UBUNTU-CVE-2026-74320

## What is CVE-2026-74320?

CVE-2026-74320 is an use after free vulnerability in Linux, published on 15 Aug 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:

fbdev: sm501fb: Fix buffer errors in OF binding code

The code that gets the frame buffer mode from OF has 'use after free',
'buffer overrun' and memory leaks.

info->edid_data isn't free if the probe functions fail or if
pd->def_mode is set.

If both the CRT and PANEL are enabled info->edid_data is used after
being freed and is freed twice.

The string returned by of_get_property(np, "mode", &len) is just
written over either the static "640x480-16@60" or the module parameter
string without any regard for the length (which is most likely longer).

Use kstrump() for the OF mode and free everything before freeing 'info.

## Which versions are affected by CVE-2026-74320?


## How do I fix CVE-2026-74320?

Apply the vendor's patch.

## Is CVE-2026-74320 being exploited?

There is no known exploitation of CVE-2026-74320 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74320 and fix it if it is affected.

What it is: CVE-2026-74320 is an use after free vulnerability in Linux, published on 15 Aug 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-2026-74320 in the wild and no public exploit code.

Affected product: Linux. 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-2026-74320/ (Markdown: https://insights.sbomify.com/CVE-2026-74320/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74320
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74320
- OSV: https://osv.dev/vulnerability/CVE-2026-74320

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74320/
Summaries are generated and may contain mistakes; the official description above is the record.