CVE-2026-98631

Medium

Description

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.

SeverityMedium
CVSS6.0
Exploit probability—
ProductMicrosoft Azl3 Kernel
PublishedOct 18, 2026
First seenOct 18, 2026

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
microsoft azl3_kernel_6.6.157.1-1No range specified—

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CVE-2026-98631 · Microsoft Azl3 Kernel · Dark Radar