---
id: CVE-2026-98611
title: 'kernel: bpf: Check params size before reading reserved fields (CVE-2026-98611)'
summary: >-
  A flaw was found in the Linux kernel's BPF (Berkeley Packet Filter) subsystem.
  The bpf_crypto_ctx_create() function attempts to read reserved fields from a
  parameter structure prior to verifying that the supplied buffer is
  sufficiently lar…
severity: medium
cvss: 4.4
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe: CWE-125
vendor: Red Hat
product: Red Hat Enterprise Linux 10
affected:
  - enterprise_linux 10
published: '2026-10-18'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T08:32:39+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98611.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98611.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98611'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2554954'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98611'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98611'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98611.mbox
  - url: 'https://git.kernel.org/stable/c/e03253f5d65ebcd2a6d479f140c3bd9c7e4fb84a'
  - url: 'https://git.kernel.org/stable/c/cd12d3e08620257fbcaa262785d7f4b9473afc7a'
  - url: 'https://git.kernel.org/stable/c/86a0e945fb645ea90233fde239cd2de79f01974c'
  - url: 'https://git.kernel.org/stable/c/a11212910cf09b2fe8db9afa41ef60c4f81879c5'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00168
epssPercentile: 0.06025
ingestedAt: '2026-10-18T15:45:12.241Z'
---

## Overview

A flaw was found in the Linux kernel's BPF (Berkeley Packet Filter) subsystem. The bpf_crypto_ctx_create() function attempts to read reserved fields from a parameter structure prior to verifying that the supplied buffer is sufficiently large. A local user capable of loading BPF programs can exploit this issue by supplying an undersized buffer, causing an out-of-bounds read from kernel memory. This flaw could lead to the exposure of sensitive kernel information or trigger a system crash resulting in a Denial of Service (DoS).

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-10-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98611.json)

**kernel: bpf: Check params size before reading reserved fields** — rated Moderate by Red Hat. Released 2026-10-18, updated 2026-10-21.

Affected:

- Red Hat Enterprise Linux 10

No fix planned:

- Red Hat Enterprise Linux 10

Not affected:

- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

## Remediation

Fix deferred