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.
Affected versions
Linux kernel versions
5.5
and later are affected. Fixed in
5.10.271,
5.15.222,
6.1.189,
6.6.158,
6.12.112,
6.18.55,
7.2.9,
7.3
and their respective stable series.
References
8 totalFrequently asked questions
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What is CVE-2026-98631?
CVE-2026-98631 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.5 onward and has been patched in 5.10.271, 5.15.222, 6.1.189 and others. CVE-2026-98631 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-98631?
Yes. CVE-2026-98631 has been patched. Fixed versions include 5.10.271, 5.15.222, 6.1.189 and others. If you are running Linux kernel 5.5 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-98631 actively exploited?
No. CVE-2026-98631 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.