Vulnerability in Linux

CVE-2026-63874

In the Linux kernel, the following vulnerability has been resolved: net: mctp: usb: fix race between urb completion and rx_retry cancellation It's possible that sequencing between setting ->stopped and cancelling the rx_retry work (in ndo_stop) could leave us with an urb queued: T1: ndo_stop T2: rx_retry_work ------------ ---------------- LD: ->stopped => false ST: ->stopped <= true usb_kill_urb() mctp_usb_rx_queue() usb_submit_urb() cancel_delayed_work_sync() That urb completion can then re-schedule rx_retry_work. Strenghen the sequencing between the stop (preventing another requeue) and the cancel by updating both atomically under a new rx lock. After setting ->rx_stopped, and cancelling pending work, we know that the requeue cannot occur, so all that's left is killing any pending urb.

EPSS: 0.002 (6.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

  • Linux — versions 0791c0327a6e4e7691d6fc5ad334c215de04dcc9, 6.15, 0

References

Frequently asked questions

What is CVE-2026-63874?
CVE-2026-63874 is a high-severity vulnerability in Linux. CVSS score: 7.8/10. Published 2026-07-19.
How severe is CVE-2026-63874?
High severity. CVSS v3 base score is 7.8 out of 10.