CVE-2025-64437 — KubeVirt Isolation Detection Flaw Allows Arbitrary File Permission Changes
KubeVirt is a virtual machine management add-on for Kubernetes. In versions before 1.5.3 and 1.6.1, the virt-handler does not verify whether the launcher-sock is a symlink or a regular file. This oversight can be exploited, for example, to change the ownership of arbitrary files on the host node to the unprivileged user with UID 107 (the same user used by virt-launcher) thus, compromising the CIA (Confidentiality, Integrity and Availability) of data on the host. To successfully exploit this vulnerability, an attacker should be in control of the file system of the virt-launcher pod. This vulnerability is fixed in 1.5.3 and 1.6.1.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+2
- Technical severity (medium)+3
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Kubevirt Kubevirt).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (file handling), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 5.0 | CVSS 3.1 | Medium | 0.8 | 3.7 | security-advisories@github.com via NIST National Vulnerability Database |
| 5.0 | CVSS 3.1 | Medium | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:L (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.23%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Monitor file creation in web directories and paths with traversal sequences (../).
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · kubevirt/kubevirt
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 5.0
- Source status changed · → Analyzed
- Record created in this database
- 2025
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
4 on the record
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-13434 Virt-controller-rhel9: kubevirt: kubevirt: multus default-network annotation injection via unvalidated tenant networkname when externalnetresourceinjection is enabled Jun 26, 2026
- Medium CVE-2026-13218 Kubevirt: kubevirt: symlink following in writetocachedfile allows host file overwrite from virt-launcher Jun 25, 2026
- Medium CVE-2026-13318 Virt-api-rhel9: kubevirt: kubevirt: ssrf in virt-api port-forward via unvalidated guest-agent-reported ip Jun 25, 2026
- Low CVE-2026-13322 Kubevirt: virt-handler-rhel9: kubevirt: unbounded virtio-serial readline in virt-handler causes oom denial of service Jun 25, 2026
- High CVE-2026-13201 Kubevirt: virt-handler-rhel9: kubevirt: safepath symlink following in virt-handler enables notify socket hijacking and node-level vm disruption Jun 24, 2026
- Medium CVE-2026-13208 Kubevirt: virt-handler-rhel9: kubevirt: virt-handler notify server trusts vmi identity from unauthenticated grpc request body Jun 24, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2025-64437 is "KubeVirt Isolation Detection Flaw Allows Arbitrary File Permission Changes", rated Medium. It affects Kubevirt (Kubevirt); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.0 describes technical severity. EPSS 0.23% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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