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PatchSiren cyber security CVE debrief

CVE-2026-63871 Linux CVE debrief

PatchSiren debrief for CVE-2026-63871, a Linux kernel Bluetooth vulnerability. The CVE record was published on 2026-07-19T15:16:54.133Z and has not been modified since then. This vulnerability is a data-race issue in the Linux kernel's Bluetooth ISO implementation, specifically affecting the hci_get_route() function calls in iso_connect_bis(), iso_connect_cis(), iso_listen_bis(), and iso_conn_big_sync(). These functions call hci_get_route() using iso_pi(sk)->dst, iso_pi(sk)->src, and iso_pi(sk)->src_type without holding lock_sock().

Vendor
Linux
Product
Unknown
CVSS
Unknown
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-19
Original CVE updated
2026-07-19
Advisory published
2026-07-19
Advisory updated
2026-07-19

Who should care

Linux kernel users and administrators should review and apply patches for CVE-2026-63871 to prevent potential Bluetooth-related attacks. Affected Linux kernel deployments should be reviewed, and owners assigned for follow-up. Compensating controls for exposed systems should be considered while remediation is scheduled and verified.

Technical summary

CVE-2026-63871 is a data-race vulnerability in the Linux kernel's Bluetooth ISO implementation. The vulnerability occurs when hci_get_route() is called without holding lock_sock(), allowing concurrent modification of iso_pi(sk)->dst, iso_pi(sk)->src, and iso_pi(sk)->src_type. This can result in data-races reported by KCSAN. The issue is resolved by snapshotting the required fields under lock_sock() before calling hci_get_route().

Defensive priority

Medium

Recommended defensive actions

  • Review and apply patches for CVE-2026-63871
  • Monitor Linux kernel updates for CVE-2026-63871 patches
  • Consider implementing compensating controls for Bluetooth-related security
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
  • Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
  • Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

Evidence for CVE-2026-63871 includes Linux kernel source code changes and KCSAN reports. The CVE record was published on 2026-07-19T15:16:54.133Z and has not been modified since then. To verify, defenders should review Linux kernel source code changes and KCSAN reports for CVE-2026-63871. Linux kernel users and administrators should review and apply patches for CVE-2026-63871 to prevent potential Bluetooth-related attacks.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-19T15:16:54.133Z and has not been modified since then.