SB20260720402 - Race condition in Linux kernel net mctp driver

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-63874)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a race condition in the mctp-usb driver when stopping the network device while rx retry work and urb completion are handled concurrently. A local user can trigger concurrent stop and retry activity to cause a denial of service.

The issue can leave a receive urb queued and its completion can reschedule retry work after device shutdown.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/54665dce982689e2fd99b32e9a0dcc204fda8a51
• https://git.kernel.org/stable/c/9c46f3ee1837f6881cb99a52ffecb2760f11dc73
• https://git.kernel.org/stable/c/d90feaa3f74bea8dafb6494631a194c70e547d94