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.
Affected versions
Linux kernel versions
6.15
and later are affected. Fixed in
6.18.36,
7.0.13,
7.1
and their respective stable series.
References
3 totalFrequently asked questions
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What is CVE-2026-63874?
CVE-2026-63874 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.15 onward and has been patched in 6.18.36, 7.0.13 and 7.1. CVE-2026-63874 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-63874?
Yes — CVE-2026-63874 has been patched. Fixed versions include 6.18.36, 7.0.13 and 7.1. If you are running Linux kernel 6.15 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-63874 actively exploited?
No — CVE-2026-63874 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.