CVE-2026-98588 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, as well as users of Linux-based systems, should assess their exposure and ensure the fix is applied. This includes reviewing and updating Linux kernel versions, monitoring system logs for potential exploitation attempts, and implementing additional security measures to prevent exploitation.

Why it matters

A vulnerability in the Linux kernel's sock_map_alloc function allows for an out-of-bounds write, potentially causing a denial of service or code execution. Linux kernel developers and maintainers, as well as users of Linux-based systems, should assess their exposure and ensure the fix is applied.

• Denial of service due to faulting access in sock_map_free
• Potential code execution due to out-of-bounds write
• Verification of Linux kernel versions and updates required
• Monitoring system logs for potential exploitation attempts

Technical summary

The sock_map_alloc function in the Linux kernel does not properly validate the max_entries value, allowing for an out-of-bounds write in sock_map_free. This can cause a faulting access, potentially leading to a denial of service or code execution. The vulnerability was triggered by syzkaller and reproduced on both a 6.6-based KASAN kernel and the upstream v7.3-rc2 kernel. Vmcore confirmed stab->map.max_entries == 0xffffffff, stab->sks == 0xffffc911ace2d000, and the faulting address sks + (s64)INT_MIN * 8 exactly at 0xffffc90dace2d000.

Defensive priority

High

Recommended defensive actions

• Review and update Linux kernel versions to ensure the fix is applied
• Monitor system logs for potential denial of service or code execution attempts
• Implement additional security measures to prevent exploitation
• Verify Linux kernel versions and updates are applied
• Monitor system logs for potential exploitation attempts
• Track exceptions and retest remediated assets
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The vulnerability was triggered by syzkaller and reproduced on both a 6.6-based KASAN kernel and the upstream v7.3-rc2 kernel. Vmcore confirmed stab->map.max_entries == 0xffffffff, stab->sks == 0xffffc911ace2d000, and the faulting address sks + (s64)INT_MIN * 8 exactly at 0xffffc90dace2d000.

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.