Kubevirt: kubevirt: symlink following in writetocachedfile allows host file overwrite from virt-launcher

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2026-13218
StatePUBLISHED
Assignerredhat
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-06-26 00:16:51 UTC
Updated2026-06-26 16:19:06 UTC
DescriptionA flaw was found in KubeVirt's virt-handler network cache handling. The WriteToCachedFile function writes data to a launcher-rooted path using os.WriteFile and os.Chown without symlink protection. A user with access to the virt-launcher container can plant a symlink at the cache file path, causing virt-handler to follow it and overwrite an arbitrary host file with JSON content and change its ownership.

Risk And Classification

Primary CVSS: v3.1 4.2 MEDIUM from [email protected]

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L

EPSS: 0.001050000 probability, percentile 0.012810000 (date 2026-06-29)

Problem Types: CWE-61 | CWE-61 UNIX Symbolic Link (Symlink) Following

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary4.2MEDIUMCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L
3.1CNACVSS4.2MEDIUMCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
Low
Availability
Low

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Red Hat Red Hat OpenShift Virtualization 4 Not specified Not specified
CNA Red Hat Red Hat OpenShift Virtualization 4 Not specified Not specified

References

ReferenceSourceLinkTags
access.redhat.com/security/cve/CVE-2026-13218 [email protected] access.redhat.com
bugzilla.redhat.com/show_bug.cgi [email protected] bugzilla.redhat.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: This issue was discovered by Huzaifa Sidhpurwala (Red Hat). (en)

Additional Advisory Data

SourceTimeEvent
CNA2026-06-24T00:00:00.000ZReported to Red Hat.
CNA2026-06-25T00:00:00.000ZMade public.

Workarounds

CNA: Ensure virtual machines use the default masquerade network binding mode where possible. Restrict pods/exec access on virt-launcher pods to only trusted administrators. Review and restrict NetworkAttachmentDefinition resources to limit which namespaces can configure bridge-type network interfaces.

© CVE.report 2026 |

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report