# CVE-2026-23208: ALSA: usb-audio: Prevent excessive number of frames

> A local attacker can trigger an out-of-bounds write in the ALSA USB audio driver, potentially leading to code execution or privilege escalation.

- **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:** 14 Feb 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-77712, BELL-CVE-2026-23208, DEBIAN-CVE-2026-23208, GHSA-gmr7-w89v-rr2q, ROOT-OS-DEBIAN-11-CVE-2026-23208, ROOT-OS-DEBIAN-12-CVE-2026-23208, ROOT-OS-DEBIAN-13-CVE-2026-23208, ROOT-OS-UBUNTU-2204-CVE-2026-23208, ROOT-OS-UBUNTU-2404-CVE-2026-23208, UBUNTU-CVE-2026-23208

## What is CVE-2026-23208?

CVE-2026-23208 is a high-severity memory corruption vulnerability in Linux kernel, published on 14 Feb 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: usb-audio: Prevent excessive number of frames

In this case, the user constructed the parameters with maxpacksize 40
for rate 22050 / pps 1000, and packsize[0] 22 packsize[1] 23. The buffer
size for each data URB is maxpacksize * packets, which in this example
is 40 * 6 = 240; When the user performs a write operation to send audio
data into the ALSA PCM playback stream, the calculated number of frames
is packsize[0] * packets = 264, which exceeds the allocated URB buffer
size, triggering the out-of-bounds (OOB) issue reported by syzbot [1].

Added a check for the number of single data URB frames when calculating
the number of frames to prevent [1].

[1]
BUG: KASAN: slab-out-of-bounds in copy_to_urb+0x261/0x460 sound/usb/pcm.c:1487
Write of size 264 at addr ffff88804337e800 by task syz.0.17/5506
Call Trace:
 copy_to_urb+0x261/0x460 sound/usb/pcm.c:1487
 prepare_playback_urb+0x953/0x13d0 sound/usb/pcm.c:1611
 prepare_outbound_urb+0x377/0xc50 sound/usb/endpoint.c:333

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-23208?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23208?

Apply the vendor's patch.

## Is CVE-2026-23208 being exploited?

There is no known exploitation of CVE-2026-23208 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-2026-23208 and fix it if it is affected.

What it is: CVE-2026-23208 is a high-severity memory corruption vulnerability in Linux kernel, published on 14 Feb 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-2026-23208 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-2026-23208/ (Markdown: https://insights.sbomify.com/CVE-2026-23208/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23208
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23208
- OSV: https://osv.dev/vulnerability/CVE-2026-23208

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23208/
Summaries are generated and may contain mistakes; the official description above is the record.