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.
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.