---
id: CVE-2026-98869
title: >-
  kernel: bpf: Infer zext_dst based on static register liveness analysis
  (CVE-2026-98869)
summary: >-
  A flaw was found in the Linux kernel's Berkeley Packet Filter (BPF) verifier.
  A local attacker could achieve privilege escalation by loading a specially
  crafted BPF program into the kernel. The vulnerability occurs because the
  verifier fai…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: vendor
cwe: CWE-681
vendor: Red Hat
product: Red Hat Enterprise Linux 10
affected:
  - enterprise_linux 10
published: '2026-10-21'
updated: '2026-10-24'
sourceUpdated: '2026-10-24T14:22:58+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98869.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98869.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98869'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2558313'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98869'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98869'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98869.mbox
  - url: 'https://git.kernel.org/stable/c/7ce090afbf725e25fff29caacce1eaf8459b1117'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00165
epssPercentile: 0.05709
ingestedAt: '2026-10-21T15:02:42.098Z'
---

## Overview

A flaw was found in the Linux kernel's Berkeley Packet Filter (BPF) verifier. A local attacker could achieve privilege escalation by loading a specially crafted BPF program into the kernel. The vulnerability occurs because the verifier fails to properly track register states across execution paths during 32-bit operations, leading to missing zero-extension instructions. Consequently, an attacker can inject arbitrary values into 64-bit registers to bypass kernel safety checks and compromise system memory.

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-10-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98869.json)

**kernel: bpf: Infer zext_dst based on static register liveness analysis** — rated Important by Red Hat. Released 2026-10-21, updated 2026-10-24.

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

Affected