CVE-2026-88265

Crun: crun: /dev/null symlink follow during stdio reopen allows host bind-mount write and chown

Published Sep 10, 2026 CVSS 3.1 · 5.6 Medium EPSS < 1% KEV · Not listed
Description
A flaw was found in crun. After pivot_root, reopening /dev/null for stdio can follow a symlink and attach a host file to container stdio, then change that file's ownership. Affected versions are crun 1.29.1 and earlier. Default configurations that mount a fresh /dev are not exposed. No fixed release is available yet.

Remediation

Vendor Workaround

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Tracking

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Advisories

No advisories available
History
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 Redhat hardened Images
Vendors & Products Redhat hardened Images
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
Description A flaw was found in crun. After pivot_root, reopening /dev/null for stdio can follow a symlink and attach a host file to container stdio, then change that file's ownership. Affected versions are crun 1.29.1 and earlier. Default configurations that mount a fresh /dev are not exposed. No fixed release is available yet.
Title Crun: crun: /dev/null symlink follow during stdio reopen allows host bind-mount write and chown
First Time appeared Redhat
Redhat hummingbird
Weaknesses CWE-59
CPEs cpe:/a:redhat:hummingbird:1
Vendors & Products Redhat
Redhat hummingbird
References
Metrics cvssV3_1

{'score': 5.6, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Nov 6, 2026, 1:13 AM
Reserved
Sep 10, 2026, 1:57 AM
Status
Awaiting Analysis
Published
Sep 10, 2026, 9:17 AM
Modified
Nov 6, 2026, 2:17 AM
Severity
Moderate
Public date
Sep 9, 2026, 12:00 AM