{"id":"CVE-2026-13218","aliases":["AZL-111647","AZL-91463","EUVD-2026-39594","GHSA-q3jc-42cq-33fj","GO-2026-6914"],"status":"published","title":"Kubevirt: kubevirt: symlink following in writetocachedfile allows host file overwrite from virt-launcher","description":"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.","severity":{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00139,"percentile":0.0332,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-61"],"published":"2026-06-25T23:23:23Z","modified":"2026-11-05T23:25:35Z","affected":[{"source":"ghsa","ecosystem":"Go","package":"kubevirt.io/kubevirt","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"1.10.0-rc.0"}]}]},{"source":"osv","ecosystem":"Azure Linux:3","package":"kubevirt-openvmm","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"1.9.0-1"}]}]},{"source":"osv","ecosystem":"Azure Linux:3","package":"kubevirt","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"1.8.4-4"}]}]},{"source":"osv","ecosystem":"Go","package":"kubevirt.io/kubevirt","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"last_affected":"1.10.0-rc.0"}]}]},{"source":"osv","ecosystem":"Go","package":"kubevirt.io/kubevirt","ranges":[{"type":"SEMVER","events":[{"introduced":"0"}]}]}],"products":[{"vendor":"kubevirt","product":"kubevirt"},{"vendor":"red hat","product":"red hat openshift virtualization 4"},{"vendor":"redhat","product":"openshift_virtualization"}],"references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-13218","tags":["vdb-entry","x_refsource_REDHAT","Vendor Advisory","Mitigation","web"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2492654","tags":["issue-tracking","x_refsource_REDHAT","Issue Tracking","Vendor Advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-13218","tags":["web","advisory"]},{"url":"https://github.com/kubevirt/kubevirt/blob/e63503d2f3a166f79f0891f8e1c3450eb39f88ac/pkg/network/cache/cache.go#L90-L103","tags":["web"]},{"url":"https://github.com/advisories/GHSA-q3jc-42cq-33fj","tags":["advisory"]},{"url":"https://github.com/kubevirt/kubevirt","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-13218","title":"Kubevirt: kubevirt: symlink following in writetocachedfile allows host file overwrite from virt-launcher","description":"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.","status":"published","published":"2026-06-25T23:23:23.228Z","modified":"2026-06-26T14:58:48.021Z","cvss":[{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-61"],"updated_at":"2026-11-02T14:19:49.885652Z"}],"euvd":[{"id":"EUVD-2026-39594","description":"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.","status":"published","published":"2026-06-25T23:23:23Z","modified":"2026-06-26T14:58:48Z","cvss":[{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L","level":"medium"}],"updated_at":"2026-11-02T18:20:24.495602Z"}],"ghsa":[{"id":"GHSA-q3jc-42cq-33fj","title":"KubeVirt virt-handler network cache symlink vulnerability allows arbitrary host file overwrite","description":"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.","status":"published","published":"2026-06-26T00:32:07Z","modified":"2026-11-04T17:23:35Z","cvss":[{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L","level":"medium"}],"cwes":["CWE-61"],"updated_at":"2026-11-04T17:24:03.876303Z"}],"nvd":[{"id":"CVE-2026-13218","description":"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.","status":"published","published":"2026-06-26T00:16:51.147Z","modified":"2026-10-25T22:10:00.15Z","cvss":[{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-61"],"updated_at":"2026-11-02T14:12:26.045561Z"}],"osv":[{"id":"GHSA-q3jc-42cq-33fj","title":"KubeVirt virt-handler network cache symlink vulnerability allows arbitrary host file overwrite","description":"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.","status":"published","published":"2026-06-26T00:32:07Z","modified":"2026-11-05T23:25:35.991938771Z","cvss":[{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L","level":"medium"}],"cwes":["CWE-61"],"updated_at":"2026-11-06T00:02:13.631839Z"},{"id":"AZL-111647","title":"CVE-2026-13218 affecting package kubevirt-openvmm 1.9.0-1","description":"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.","status":"published","published":"2026-06-26T00:16:51Z","modified":"2026-11-05T05:40:51Z","updated_at":"2026-11-05T16:41:18.705965Z"},{"id":"AZL-91463","title":"CVE-2026-13218 affecting package kubevirt 1.8.4-4","description":"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.","status":"published","published":"2026-06-26T00:16:51Z","modified":"2026-11-05T05:40:51Z","updated_at":"2026-11-05T16:41:25.633663Z"},{"id":"GO-2026-6914","title":"KubeVirt virt-handler network cache symlink vulnerability allows arbitrary host file overwrite in kubevirt.io/kubevirt","description":"KubeVirt virt-handler network cache symlink vulnerability allows arbitrary host file overwrite in kubevirt.io/kubevirt","status":"published","published":"2026-11-05T22:55:09Z","modified":"2026-11-05T23:15:16.262333672Z","updated_at":"2026-11-06T00:02:13.631839Z"}]}}