CVE-2026-53357 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, Bluetooth protocol implementers, and organizations using Linux-based systems with Bluetooth capabilities should be aware of this vulnerability. This vulnerability can be exploited by an unprivileged attacker to cause a denial-of-service or potentially execute arbitrary code.

Technical summary

The vulnerability is caused by a race condition between the l2cap_sock_cleanup_listen() function and the l2cap_conn_del() function. The l2cap_sock_cleanup_listen() function walks the children of a listening socket on close, while the l2cap_conn_del() function frees the child socket and its l2cap_chan. This can result in a use-after-free error when the cleanup_listen() function uses the freed child socket and l2cap_chan. The fix involves taking a reference to the child socket in bt_accept_dequeue() and calling sock_put() in the callers.

Defensive priority

High

Recommended defensive actions

• Review and apply the provided patch to the Linux kernel
• Monitor Linux kernel updates for future fixes
• Implement additional logging and monitoring for Bluetooth-related activity
• Consider using SELinux or other Mandatory Access Control systems to restrict Bluetooth protocol access
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record was published on 2026-07-02T15:17:03.103Z and last modified on 2026-07-18T08:16:36.343Z. The NVD entry is currently Awaiting Analysis. Multiple source references are provided, including kernel.org links to specific commits.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.