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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
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.
- Record
CVE-2026-13218- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L - Weakness
- CWE-61
- Updated
- 2026-11-02
EUVDEUVD-2026-39594
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.
- Record
EUVD-2026-39594- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-q3jc-42cq-33fj
KubeVirt virt-handler network cache symlink vulnerability allows arbitrary host file overwrite
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.
- Record
GHSA-q3jc-42cq-33fj- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L - Weakness
- CWE-61
- Updated
- 2026-11-04
NVD
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.
- Record
CVE-2026-13218- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L - Weakness
- CWE-61
- Updated
- 2026-11-02
OSVGHSA-q3jc-42cq-33fj
KubeVirt virt-handler network cache symlink vulnerability allows arbitrary host file overwrite
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.
- Record
GHSA-q3jc-42cq-33fj- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L - Weakness
- CWE-61
- Updated
- 2026-11-06
OSVAZL-111647 No score
CVE-2026-13218 affecting package kubevirt-openvmm 1.9.0-1
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.
- Record
AZL-111647- Updated
- 2026-11-05
OSVAZL-91463 No score
CVE-2026-13218 affecting package kubevirt 1.8.4-4
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.
- Record
AZL-91463- Updated
- 2026-11-05
OSVGO-2026-6914 No score
KubeVirt virt-handler network cache symlink vulnerability allows arbitrary host file overwrite in kubevirt.io/kubevirt
KubeVirt virt-handler network cache symlink vulnerability allows arbitrary host file overwrite in kubevirt.io/kubevirt
- Record
GO-2026-6914- Updated
- 2026-11-06
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
kubevirt.io/kubevirtGo |
through 1.10.0-rc.0 | None known |
kubevirt-openvmmAzure Linux:3 |
through 1.9.0-1 | None known |
kubevirtAzure Linux:3 |
through 1.8.4-4 | None known |
kubevirt.io/kubevirtGo |
All versions | None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, aliases, references | OSV | |
| affected, references | OSV | |
| affected, facts, references | GitHub Advisories | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-13218 is a medium vulnerability (CVSS 4.2) in Kubevirt, published June 25, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.14%, the 3rd percentile. No source names a fixed version.