CVE-2026-98098 Linux CVE debrief

Who should care

Linux kernel developers and administrators responsible for configuring and maintaining Linux systems using TIPC protocol, as well as operators and security teams managing and securing these systems, should be aware of this vulnerability and take necessary actions to mitigate potential impacts.

Why it matters

This vulnerability can impact Linux systems using TIPC protocol, requiring attention from kernel developers and administrators to ensure proper configuration and mitigate potential impacts.

• Potential denial of service due to NULL pointer dereference
• Loss of node or link up/down event notifications for user-space applications
• Need for verification of Linux kernel configurations and TIPC protocol settings

Technical summary

The Linux kernel's TIPC protocol has a vulnerability that can cause a NULL pointer dereference when the number of local publications exceeds TIPC_MAX_PUBL (65535). This issue can be triggered when user-space applications bind a large number of service addresses to one or more sockets. The vulnerability causes user-space applications subscribing to node or link up/down events to stop receiving notifications and can lead to a NULL pointer dereference if 'tipc_nametbl_publish()' fails. To address this, protocol service types such as node state, link state, and topology server should be inserted into the name table unconditionally, ensuring users subscribing to these types always receive notifications. Additionally

Defensive priority

Medium

Recommended defensive actions

• Review and update Linux kernel configurations to ensure TIPC protocol is properly configured
• Monitor system logs for potential NULL pointer dereference errors
• Consider implementing compensating controls to mitigate potential impacts
• Verify Linux kernel configurations and TIPC protocol settings
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The Linux kernel's TIPC protocol has a vulnerability that can cause a NULL pointer dereference when the number of local publications exceeds TIPC_MAX_PUBL. This issue can be triggered when user-space applications bind a large number of service addresses to one or more sockets.

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.