---
id: CVE-2026-84042
title: A flaw was found in crun
summary: >-
  A flaw was found in crun. When crun is built with libkrun and a container is
  started rootful with passt networking (krun.use_passt), crun can execute
  attacker-controlled payload from the container image with host root
  privileges. The iss…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H'
cwe:
  - CWE-269
vendor: Red Hat
product: crun
affected:
  - crun (all versions)
  - 'container-tools:rhel8/crun'
  - crun (all versions)
  - crun
  - crun
  - openshift/ose-rhel-coreos-8
  - openshift/ose-rhel-coreos-9
published: '2026-09-10'
updated: '2026-09-15'
sourceUpdated: '2026-09-15T17:17:28.130'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84042'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-84042'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2531222'
    label: secalert@redhat.com
  - url: 'https://github.com/containers/crun/'
    label: secalert@redhat.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-84042.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-84042'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84042'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-10T17:34:01.587198Z'
epss: 0.00137
epssPercentile: 0.02518
ingestedAt: '2026-09-11T14:42:19.866Z'
---

## Overview

A flaw was found in crun. When crun is built with libkrun and a container is started rootful with passt networking (krun.use_passt), crun can execute attacker-controlled payload from the container image with host root privileges. The issue is a regression in crun 1.29. It affects crun >= 1.29

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-84042.json)