CVE-2026-84042

Crun: crun: rootful krun with passt executes container payload as host root

Published Sep 10, 2026 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
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

Vendor Workaround

Do not run untrusted images with krun and passt until a fixed crun is released.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:/a:redhat:enterprise_linux:10 cpe:/o:redhat:enterprise_linux:10.3
References
Type Values Removed Values Added
CPEs cpe:/a:redhat:enterprise_linux:9 cpe:/a:redhat:enterprise_linux:9::appstream
References
Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
cpe:/a:redhat:enterprise_linux:10
cpe:/a:redhat:enterprise_linux:8
cpe:/a:redhat:enterprise_linux:9
cpe:/a:redhat:openshift:5
Type Values Removed Values Added
First Time appeared Redhat enterprise Linux
Redhat openshift
CPEs cpe:/a:redhat:openshift:4
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat enterprise Linux
Redhat openshift
Type Values Removed Values Added
First Time appeared Containers
Containers crun
Redhat hardened Images
Vendors & Products Containers
Containers crun
Redhat hardened Images
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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
Title Crun: crun: rootful krun with passt executes container payload as host root
First Time appeared Redhat
Redhat hummingbird
Weaknesses CWE-269
CPEs cpe:/a:redhat:hummingbird:1
Vendors & Products Redhat
Redhat hummingbird
References
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Nov 11, 2026, 12:52 PM
Reserved
Sep 1, 2026, 3:55 AM
Status
Awaiting Analysis
Published
Sep 10, 2026, 9:17 AM
Modified
Nov 11, 2026, 1:17 PM
Severity
Important
Public date
Sep 10, 2026, 12:00 AM