CVE-2026-13218 | Kubevirt: kubevirt: symlink following in writetocachedfile allows host file overwrite from virt-launcher

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.

Published: 2026-06-25 Last update: 2026-06-26 Assigner: [email protected] Source: [email protected]
NVD Status：Awaiting Analysis，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-13218 is rated Low Risk (17.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.10%). Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-13218

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-26 — 0.10% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-13218

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.2 3.1 MEDIUM
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 1.1 2.7 [email protected]

Weakness enumeration for CVE-2026-13218

GitHub Security Advisory for CVE-2026-13218

GHSA-q3jc-42cq-33fj · Severity: medium — A flaw was found in KubeVirt's virt-handler network cache handling. The WriteToCachedFile...

OS Trackers for CVE-2026-13218

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2026-13218
suse medium — https://www.suse.com/security/cve/CVE-2026-13218/

Affected software / configurations for CVE-2026-13218

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-13218

cvelogic Threat Intelligence