# CVE-2026-31581: ALSA: 6fire: fix use-after-free on disconnect

> A use-after-free vulnerability in the Linux kernel's ALSA 6fire USB driver allows attackers to execute arbitrary code or escalate privileges via device disconnection.

- **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:** 24 Apr 2026
- **Updated:** 14 Jun 2026
- **Also known as:** BELL-CVE-2026-31581, DEBIAN-CVE-2026-31581, GHSA-8wc2-723q-hf3g, ROOT-OS-DEBIAN-11-CVE-2026-31581, ROOT-OS-DEBIAN-12-CVE-2026-31581, ROOT-OS-DEBIAN-13-CVE-2026-31581, ROOT-OS-UBUNTU-2204-CVE-2026-31581, ROOT-OS-UBUNTU-2404-CVE-2026-31581, UBUNTU-CVE-2026-31581

## What is CVE-2026-31581?

CVE-2026-31581 is a high-severity use after free vulnerability in Linux kernel, published on 24 Apr 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:

ALSA: 6fire: fix use-after-free on disconnect

In usb6fire_chip_abort(), the chip struct is allocated as the card's
private data (via snd_card_new with sizeof(struct sfire_chip)).  When
snd_card_free_when_closed() is called and no file handles are open, the
card and embedded chip are freed synchronously.  The subsequent
chip->card = NULL write then hits freed slab memory.

Call trace:
  usb6fire_chip_abort sound/usb/6fire/chip.c:59 [inline]
  usb6fire_chip_disconnect+0x348/0x358 sound/usb/6fire/chip.c:182
  usb_unbind_interface+0x1a8/0x88c drivers/usb/core/driver.c:458
  ...
  hub_event+0x1a04/0x4518 drivers/usb/core/hub.c:5953

Fix by moving the card lifecycle out of usb6fire_chip_abort() and into
usb6fire_chip_disconnect().  The card pointer is saved in a local
before any teardown, snd_card_disconnect() is called first to prevent
new opens, URBs are aborted while chip is still valid, and
snd_card_free_when_closed() is called last so chip is never accessed
after the card may be freed.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-31581?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-31581?

Apply the vendor's patch.

## Is CVE-2026-31581 being exploited?

There is no known exploitation of CVE-2026-31581 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-2026-31581 and fix it if it is affected.

What it is: CVE-2026-31581 is a high-severity use after free vulnerability in Linux kernel, published on 24 Apr 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-2026-31581 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-2026-31581/ (Markdown: https://insights.sbomify.com/CVE-2026-31581/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31581
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31581
- OSV: https://osv.dev/vulnerability/CVE-2026-31581

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31581/
Summaries are generated and may contain mistakes; the official description above is the record.