Junglewise Threat Intelligence

CVE-2026-63946: Linux kernel use-after-free in Bluetooth ISO iso_recv_frame

CVE-2026-63946 · Severity: info · CVSS 0 · Published 2026-07-19

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A security vulnerability has been identified in the Linux kernel's Bluetooth subsystem. This flaw could allow a local attacker to cause a system crash or potentially execute unauthorized actions by exploiting a timing issue during Bluetooth data processing. The issue specifically affects systems using Bluetooth ISO sockets, which are commonly used for advanced audio streaming.

Technical details

A use-after-free (UAF) vulnerability exists in net/bluetooth/iso.c within the iso_recv_frame function. The vulnerability is caused by a race condition where conn->sk is accessed after the iso_conn_lock is released without holding a proper reference count. A concurrent call to iso_sock_kill() can free the socket object while iso_recv_frame is still processing it, leading to a UAF during sk->sk_state checks or sock_queue_rcv_skb() operations. The fix implements proper reference counting using iso_sock_hold() while the lock is held to ensure the socket remains valid during processing.

Affected products

  • Linux Linux kernel 6.0 to 7.0.11

Timeline

  • 2026-07-19: advisory: NVD publication date
  • 2026-05-28: patched: Initial fix committed to mainline kernel

References

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