CVE-2026-97958 Linux CVE debrief

Who should care

Linux kernel administrators and security teams should assess exposure and verify system configurations to prevent potential Hung Task splat errors. They should also monitor system logs for Hung Task splat errors and update the Linux kernel to the latest version if necessary.

Why it matters

A vulnerability in the Linux kernel's net/sched: cls_api has been resolved. Linux kernel administrators should assess exposure and verify system configurations to prevent potential Hung Task splat errors.

• Verify Linux kernel configurations for net/sched: cls_api
• Monitor system logs for Hung Task splat errors

Technical summary

The vulnerability occurs in the Linux kernel's net/sched: cls_api. A netlink socket can send RTM_GETCHAIN requests repeatedly without receiving the responses, causing tc_ctl_chain() to hog CPU and trigger a Hung Task splat. The replay logic is unnecessary for RTM_GETCHAIN and was applied only for RTM_NEWCHAIN. This issue can impact system performance and stability. Linux kernel administrators should assess exposure and verify system configurations to prevent potential Hung Task splat errors. The vulnerability can be mitigated by updating the Linux kernel to the latest version.

Defensive priority

Linux kernel administrators should assess exposure and verify system configurations.

Recommended defensive actions

• Review and verify Linux kernel configurations for net/sched: cls_api
• Monitor system logs for Hung Task splat errors
• Update Linux kernel to the latest version if necessary
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• 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

Evidence notes

The vulnerability was resolved by applying the replay logic only for RTM_NEWCHAIN. The NVD entry is currently null. Further review of system configurations and kernel updates is recommended to ensure system security and stability. Linux kernel administrators should verify system configurations and monitor system logs for Hung Task splat errors.

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.