CVE intelligence

CVE-2026-98631

Vulnerability intelligence

Published Oct 18, 2026Sources checked Oct 21, 2026

N/ACVSS not listedScore unavailable

What this means

Review the available evidence

CVE-2026-98631. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Oct 20, 2026

Release Notes

CISA KEVNot listedBased on the latest collected catalog

EPSS0.2%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-98631?

In the Linux kernel, the following vulnerability has been resolved:

xsk: Use a 32-bit compare in xsk_map_gen_lookup

xsk_map_gen_lookup() loads a u32 key and compares it with max_entries using BPF_JMP_IMM. BPF immediates are sign-extended to 64 bits, so a max_entries value of 0x80000000 or higher becomes a threshold larger than every zero-extended 32-bit key.

An out-of-range index then skips the bounds check and the generated lookup reads past xsk_map[].

Compare with BPF_JMP32_IMM so the check stays in 32-bit unsigned range.

Source: NVD