CVE-2026-53011 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, network administrators, and security teams responsible for Linux-based systems should be aware of this vulnerability. The vulnerability's impact could allow for privilege escalation or denial of service attacks. Linux distributions and vendors may need to patch their kernels to address this issue.

Technical summary

The vulnerability occurs in the advance_sched() function of the net/sched taprio. When should_change_schedules() returns true, switch_schedules() is called to promote the admin schedule to oper. However, 'next' still points into an entry of the old oper schedule, which is queued for RCU freeing via call_rcu(). This results in a use-after-free error when accessing 'next->end_time' and rcu_assign_pointer(q->current_entry, next). The fix involves selecting 'next' from the new oper schedule immediately after switch_schedules() and using its pre-calculated end_time.

Defensive priority

Apply kernel patches or updates from Linux distributions or vendors. Review and update Linux kernel configurations to ensure secure settings.

Recommended defensive actions

• Apply kernel patches or updates from Linux distributions or vendors.
• Review and update Linux kernel configurations to ensure secure settings.
• Monitor Linux kernel security advisories and updates.
• Perform regular vulnerability scans and risk assessments.
• Implement compensating controls, such as network segmentation and access controls.

Evidence notes

The CVE record and NVD detail provide information on the vulnerability. The Linux kernel source code references are provided, but their relevance and accuracy are uncertain. The CVSS score and vector are provided, but their interpretation may require additional context.

Official resources