Junglewise Threat Intelligence

CVE-2026-53256: Linux Kernel use-after-free in Bluetooth RFCOMM socket handling

CVE-2026-53256 · Severity: info · CVSS 5.5 · Published 2026-06-25

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A race condition vulnerability was identified in the Linux kernel's Bluetooth RFCOMM implementation. This flaw could allow a local attacker to cause a system crash or potentially execute unauthorized code by exploiting a timing issue when a Bluetooth connection is established at the same time a socket is being closed. This primarily impacts system stability and availability.

Technical details

A use-after-free vulnerability exists in net/bluetooth/rfcomm/sock.c due to a race condition between rfcomm_connect_ind() and socket release. The function rfcomm_get_sock_by_channel() scans the rfcomm_sk_list and returns a listener socket without incrementing its reference count. If the listener socket is closed and freed via rfcomm_sock_kill() before rfcomm_connect_ind() can lock it, a slab-use-after-free occurs in lock_sock_nested(). The fix involves taking a proper reference on the listener socket while holding the list lock and verifying the socket state after re-locking.

Affected products

  • Linux Linux Kernel 2.6.12-rc2 to 6.14

Timeline

  • 2026-05-28: other: Vulnerability reported by Zhang Cen
  • 2026-06-19: patched: Fix committed to stable kernel trees
  • 2026-06-25: disclosed: CVE published

References

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