# CVE-2026-74502: ALSA: ump: fix double free of out_cvts on rawmidi error


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** BELL-CVE-2026-74502, DEBIAN-CVE-2026-74502, GHSA-rpcv-w828-3j36, UBUNTU-CVE-2026-74502

## What is CVE-2026-74502?

CVE-2026-74502 is a vulnerability in Linux, published on 15 Aug 2026. 

### Official description

In the Linux kernel, the following vulnerability has been resolved:

ALSA: ump: fix double free of out_cvts on rawmidi error

snd_ump_attach_legacy_rawmidi() allocates the legacy conversion array
ump->out_cvts and, on the snd_rawmidi_new() error path, frees it with
kfree() but leaves ump->out_cvts pointing at the freed memory.  When the
endpoint is later torn down, snd_ump_endpoint_free() frees ump->out_cvts
a second time, resulting in a double free.

The host snd-usb-audio driver attaches the legacy rawmidi for any USB
MIDI 2.0 (UMP) device, so a device that makes snd_rawmidi_new() fail
reaches this path on enumeration.

Clear ump->out_cvts after freeing it on the error path so it is not
freed again during teardown.

Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>

## Which versions are affected by CVE-2026-74502?


## How do I fix CVE-2026-74502?

Upgrade to a fixed version.

## Is CVE-2026-74502 being exploited?

There is no known exploitation of CVE-2026-74502 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74502 and fix it if it is affected.

What it is: CVE-2026-74502 is a vulnerability in Linux, published on 15 Aug 2026. 
Exploitation: There is no known exploitation of CVE-2026-74502 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-2026-74502/ (Markdown: https://insights.sbomify.com/CVE-2026-74502/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74502
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74502
- OSV: https://osv.dev/vulnerability/CVE-2026-74502

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74502/
Summaries are generated and may contain mistakes; the official description above is the record.