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Fencer Intel
medium 4.2

CVE-2026-13218 json

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

published 4mo ago modified 4d ago also GHSA-q3jc-42cq-33fj , GO-2026-6914 , EUVD-2026-39594

cvss
4.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 3%
public exploits
0
none known

Summary

A 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.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-13218 updated cvss 4.2

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

  • Red Hat OpenShift Virtualization 4 container-native-virtualization/virt-handler, container-native-virtualization/virt-handler-rhel9
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
4mo ago

Exploit prediction

0.14% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 4.2 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L
GitHub 3.1 4.2 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L

Affected packages

ecosystem package affected fixed in
go kubevirt.io/kubevirt
<=1.10.0-rc.0
all versions
 no fix listed

Affected products

  • Red Hat Red Hat OpenShift Virtualization 4

Classification

Weakness
  • CWE-61 UNIX Symbolic Link (Symlink) Following

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.