CVE-2026-53270
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk3th percentile — higher than 3% of all known CVEs
Summary
In the Linux kernel IPVS module, a vulnerability was found where during service editing (ip_vs_edit_service), the pointer to the old scheduler (svc->scheduler) was cleared only after the scheduler module initiated RCU callbacks. This could cause the old scheduler to be used after its data (sched_data) was freed after the RCU grace period, leading to memory errors.
Risk Assessment
The organization is at risk of system crashes, memory leaks, or unpredictable network traffic behavior when using IPVS with dynamic scheduler changes. This could lead to service disruptions in load balancing.
Recommendation
Immediately update the Linux kernel to a version containing the fix (commit addressing the vulnerability). If an update is not possible, avoid dynamic IPVS scheduler changes until the patch is applied.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: ipvs: clear the svc scheduler ptr early on edit ip_vs_edit_service() while unbinding the old scheduler clears the svc->scheduler ptr after the scheduler module initiates RCU callbacks. This can cause packets to use the old scheduler at the time when svc->sched_data is already freed after RCU grace period. Fix it by clearing the ptr early in ip_vs_unbind_scheduler(), before the done_service method schedules any RCU callbacks. Also, if the new scheduler fails to initialize when replacing the old scheduler, try to restore the old scheduler while still returning the error code.