CVE-2026-80683 Linux CVE debrief

Who should care

Linux kernel users, administrators, and developers should be aware of this vulnerability and take necessary actions to assess and mitigate the risk. They should prioritize assessment and patching due to the high CVSS score of 8.8 and HIGH severity classification. Affected operator, platform, vulnerability-management, and security-team impact should be considered. Compensating controls for exposed systems and monitoring, detection, and logs for exposed assets that need extra review are recommended while remediation is scheduled and verified. Exceptions, retest remediated assets, and close the item only after evidence is documented are also important. Inventory and track Linux kernel versions across the environment to ensure all deployments are accounted for and patched accordingly. This includes reviewing 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. Track exceptions, retest remediated assets, and close the item only after evidence is documented. Review compensating controls for exposed systems while remediation is scheduled and verified. Check relevant monitoring, detection, and logs for exposed assets that need extra review. Asset inventory and source tracking are crucial for managing this vulnerability effectively. Rollback/change windows should be considered for patching and mitigating the vulnerability. Vendor patch guidance and exposure review are essential steps in addressing this vulnerability. Monitoring and compensating controls can help mitigate the risk while patching is in progress. Proper asset inventory and tracking can help ensure that all affected systems are identified and remediated. Implementing a robust vulnerability management process can help prevent similar issues in the future. Security teams should work closely with system administrators and developers to ensure that all necessary steps are taken to mitigate this vulnerability. By taking a proactive and comprehensive approach, organizations can minimize the risk associated with this vulnerability and protect their systems and

Technical summary

The Linux kernel Bluetooth SCO subsystem has a use-after-free vulnerability. When close() races with the controller's Disconnection Complete event, it leads to a reference count underflow and use-after-free. The bug was fixed by giving the socket its own sco_conn reference. The vulnerability is caused by a use-after-free issue in the Bluetooth SCO (Synchronous Connection-Oriented) subsystem of the Linux kernel.

Defensive priority

This vulnerability has a high CVSS score of 8.8 and is classified as HIGH severity. Linux kernel users should prioritize assessment and patching.

Recommended defensive actions

• Assess if Linux kernel version used is vulnerable
• Apply patch or update to fixed version
• Monitor Bluetooth SCO usage and system logs for suspicious activity
• Consider compensating controls like firewall rules or network segmentation
• Inventory and track Linux kernel versions across the environment

Evidence notes

The vulnerability is caused by a use-after-free issue in the Bluetooth SCO (Synchronous Connection-Oriented) subsystem of the Linux kernel. When the close() operation races with the controller's Disconnection Complete event, it leads to a reference count underflow and use-after-free. The bug was fixed by giving the socket its own sco_conn reference.

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.