CVE-2026-98647

Kernel oops via unchecked BTF element size

Published Oct 18, 2026 · Updated Oct 18, 2026

Divide-by-zero in the Linux BPF verifier allows local users to trigger a kernel oops by loading a program with crafted BTF metadata. In kernel/bpf/btf.c, btf_struct_walk() reduces a flexible-array access offset modulo the element size without rejecting zero-sized structures. Reaching the fault requires permission to load the relevant BPF program and a PTR_TO_BTF_ID pointer without MEM_ALLOC; the disclosed result is a kernel divide-error oops, not arbitrary code execution.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Divide-by-zero in the Linux BPF verifier allows local users to trigger a kernel oops by loading a program with crafted BTF metadata. In kernel/bpf/btf.c, btf_struct_walk() reduces a flexible-array access offset modulo the element size without rejecting zero-sized structures. Reaching the fault requires permission to load the relevant BPF program and a PTR_TO_BTF_ID pointer without MEM_ALLOC; the disclosed result is a kernel divide-error oops, not arbitrary code execution.

The record

CVE
CVE-2026-98647
Published
Oct 18, 2026
Updated
Oct 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.8
  2. Affected versionversion=9c5f8a1008a121e4c6b24af211034e24b0b63081 <172756f02663ad45c889c001c1a8cb4082a01a05
  3. Affected versionversion=9c5f8a1008a121e4c6b24af211034e24b0b63081 <1ea3820937f8022e044c41c6e95c84b02741b45f
  4. Affected versionversion=9c5f8a1008a121e4c6b24af211034e24b0b63081 <63af086cb5fa6f72fd924f86bea4c2194da663a2
  5. Affected versionversion=9c5f8a1008a121e4c6b24af211034e24b0b63081 <8eb4cd72daad3a9ee63d2281bbdd16ce6d9406b1
  6. Affected versionversion=9c5f8a1008a121e4c6b24af211034e24b0b63081 <934e9ba9f8d05656a48624710be67ca4dc8482e6
  7. Affected versionversion=9c5f8a1008a121e4c6b24af211034e24b0b63081 <b0b3dc66529676228cb938cbcad66920f735c223
  8. Affected versionversion=9c5f8a1008a121e4c6b24af211034e24b0b63081 <b8fa56722e9c43bcd59c51fe4c7edd5f4158a11b

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=5.8; version=9c5f8a1008a121e4c6b24af211034e24b0b63081 <172756f02663ad45c889c001c1a8cb4082a01a05; version=9c5f8a1008a121e4c6b24af211034e24b0b63081 <1ea3820937f8022e044c41c6e95c84b02741b45f; version=9c5f8a1008a121e4c6b24af211034e24b0b63081 <63af086cb5fa6f72fd924f86bea4c2194da663a2; version=9c5f8a1008a121e4c6b24af211034e24b0b63081 <8eb4cd72daad3a9ee63d2281bbdd16ce6d9406b1; version=9c5f8a1008a121e4c6b24af211034e24b0b63081 <934e9ba9f8d05656a48624710be67ca4dc8482e6; version=9c5f8a1008a121e4c6b24af211034e24b0b63081 <b0b3dc66529676228cb938cbcad66920f735c223; version=9c5f8a1008a121e4c6b24af211034e24b0b63081 <b8fa56722e9c43bcd59c51fe4c7edd5f4158a11b

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

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No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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