CVE-2026-43023 Linux CVE debrief

Who should care

Linux system administrators, security teams, and developers using Bluetooth SCO functionality should assess exposure and prioritize remediation. They should verify kernel versions to determine potential impact and apply fixed commits or upgrade to unaffected kernel versions if necessary. Additionally, they should monitor for potential use-after-free exploitation attempts and review compensating controls for exposed systems while remediation is scheduled.

Why it matters

This vulnerability affects Linux kernel versions prior to the fixed commits. Linux system administrators and security teams should assess exposure, prioritize remediation, and verify kernel versions to determine potential impact.

• Verify kernel versions to determine exposure.
• Assess Bluetooth SCO usage and potential impact on Linux systems.
• Apply fixed commits or upgrade to unaffected kernel versions.
• Monitor for potential use-after-free exploitation attempts.

Technical summary

The Linux kernel's Bluetooth SCO implementation has a race condition vulnerability in sco_sock_connect(). Concurrent connect() syscalls can pass checks and enter sco_connect(), leading to use-after-free. Affected versions require upgrading to fixed commits. The vulnerability is caused by a lack of proper synchronization in the sco_sock_connect() function, which allows multiple connections to be established simultaneously, leading to a use-after-free condition. This vulnerability affects Linux kernel versions prior to the fixed commits.

Defensive priority

High

Recommended defensive actions

• Review and apply the fixed commits from the Linux kernel repository.
• Inventory Linux systems using Bluetooth SCO and assess exposure.
• Verify kernel versions and upgrade to unaffected versions if necessary.
• Monitor for potential use-after-free 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.

Evidence notes

The CVE record and source item provide details on the vulnerability, including a description of the buggy scenario and affected versions. However, the corpus does not establish exploitation or impact, and remediation requires verification from official sources.

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.