Kubernetes NFS CSI Driver Path Traversal via unvalidated subDir
CVE-2026-3864 Published on March 20, 2026
CSI Driver for NFS path traversal via subDir may delete unintended directories on the NFS server
A vulnerability was discovered in the Kubernetes CSI Driver for NFS where the subDir parameter in volume identifiers was insufficiently validated. Attackers with the ability to create PersistentVolumes referencing the NFS CSI driver could craft volume identifiers containing path traversal sequences (../). During volume deletion or cleanup operations, the driver could operate on unintended directories outside the intended managed path within the NFS export. This may lead to deletion or modification of directories on the NFS server.
Vulnerability Analysis
CVE-2026-3864 is exploitable with network access, and requires user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, a high impact on integrity and availability.
Weakness Type
What is a Directory traversal Vulnerability?
The software uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the software does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
CVE-2026-3864 has been classified to as a Directory traversal vulnerability or weakness.
Affected Versions
Kubernetes CSI Driver for NFS:- Before 4.13.1 is affected.
- Version 4.13.1 is unaffected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.