Answer in brief
CVE-2026-63874 records a Unknown severity vulnerability in net: mctp: usb: fix race between urb completion and rx_retry cancellation. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=0791c0327a6e4e7691d6fc5ad334c215de04dcc9 <9c46f3ee1837f6881cb99a52ffecb2760f11dc73 || >=0791c0327a6e4e7691d6fc5ad334c215de04dcc9 <d90feaa3f74bea8dafb6494631a194c70e547d94 || >=0791c0327a6e4e7691d6fc5ad334c215de04dcc9 <54665dce982689e2fd99b32e9a0dcc204fda8a51 | 9c46f3ee1837f6881cb99a52ffecb2760f11dc73, d90feaa3f74bea8dafb6494631a194c70e547d94, 54665dce982689e2fd99b32e9a0dcc204fda8a51 |
| Linux/Linuxgeneric | 6.15 | Not reported |
Published upstream
Jul 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
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.
Quoted source text, attributed separately from HOL analysis.