CVE-2026-63865 Linux CVE debrief

Who should care

Linux kernel users and administrators should review the vulnerability details and apply patches if available. The vulnerability has a medium priority for Linux kernel users and administrators. Linux kernel users should verify the vulnerability details and apply patches if available.

Technical summary

The Linux kernel vulnerability involves a problem with bpf_lsm_task_to_inode() and bpf_lsm_inet_conn_established() functions. These functions are called under rcu_read_lock() and from softirq context, respectively, which restricts their use in sleepable LSM programs. The vulnerability has a medium priority for Linux kernel users and administrators. Linux kernel users should review the vulnerability details and apply patches if available.

Defensive priority

Medium priority for Linux kernel users and administrators.

Recommended defensive actions

• Review Linux kernel patches and updates
• Apply patches if available
• Monitor Linux kernel security advisories
• Verify Linux kernel deployments in managed environments
• Review compensating controls for exposed systems
• Check relevant monitoring, detection, and logs for exposed assets
• Track exceptions and retest remediated assets

Evidence notes

The CVE record and NVD entry provide limited information about the vulnerability. Further investigation and review of Linux kernel patches and updates are necessary. Linux kernel users should verify the vulnerability details and apply patches if available. The vulnerability involves a problem with bpf_lsm_task_to_inode() and bpf_lsm_inet_conn_established() functions. These functions are called under rcu_read_lock() and from softirq context, respectively, which restricts their use in sleepable LSM programs. Evidence limits suggest that additional details may be required for thorough vulnerability assessment.

Official resources