CVE-2026-63945 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, Bluetooth protocol implementers, and organizations using Linux-based systems with Bluetooth functionality should be aware of this vulnerability. These stakeholders should review the official advisory or CVE record to validate affected scope, severity, and vendor guidance. They should also plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.

Technical summary

The Linux kernel's Bluetooth ISO implementation has a vulnerability that can cause a NULL pointer dereference or use-after-free. The `iso_sock_clear_timer` function reads `iso_pi(sk)->conn` twice without holding the socket lock, which can lead to a race condition with `iso_conn_del` and `iso_chan_del` functions. To fix this, `iso_sock_clear_timer` is now serialized with the socket lock. The affected product context is the Linux kernel, and the defensive impact is related to the potential for a denial-of-service or code execution. The source-grounded technical framing is based on the official advisory or CVE record.

Defensive priority

Medium-High

Recommended defensive actions

• Review and apply the provided kernel patches to ensure the Bluetooth ISO implementation is properly synchronized.
• Monitor Linux kernel updates and apply patches promptly.
• Implement additional logging and monitoring to detect potential exploitation attempts.
• 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

The CVE record was published on 2026-07-19T16:17:13.107Z and has not been modified since then. The NVD entry is currently Received. There is no additional information available about the vulnerability beyond what is provided in the CVE record and NVD entry. Defenders should verify the affected scope and severity based on the official advisory or CVE record.

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.