CVE-2026-6437: AWS EFS CSI Driver Mount Option Injection
Summary The Amazon EFS CSI Driver is a Container Storage Interface driver that allows Kubernetes clusters to use Amazon Elastic File System. An issue exists where, under certain circumstances, unsanitized values in the volumeHandle and mounttargetip fields are passed directly to the mount command, allowing injection of arbitrary mount options.
Impact An actor with PersistentVolume creation privileges can inject arbitrary mount options by appending comma-separated values to the Access Point ID in volumeHandle or to the mounttargetip volumeAttribute. The mount utility parses comma-separated values as separate options, causing the injected options to be applied to the filesystem mount without authorization.
Impacted versions: <= v3.0.0
Patches This issue has been addressed in Amazon EFS CSI Driver version v3.0.1. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.
Workarounds Restrict PersistentVolume and StorageClass creation to cluster administrators using Kubernetes RBAC, preventing untrusted users from supplying arbitrary field values.
References If you have any questions or comments about this advisory, we ask that you contact AWS Security via our vulnerability reporting page or directly via email to aws-security@amazon.com. Please do not create a public GitHub issue.
Acknowledgement We would like to thank Shaul Ben-Hai from Sentinel One for collaborating on this issue through the coordinated vulnerability disclosure process.
Other sources
Improper neutralization of argument delimiters in the volume handling component in AWS EFS CSI Driver (aws-efs-csi-driver) before v3.0.1 allows remote authenticated users with PersistentVolume creation permissions to inject arbitrary mount options via comma injection.
To remediate this issue, users should upgrade to version v3.0.1
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
go/github.com/kubernetes-sigs/aws-efs-csi-driverto a version that resolves this vulnerability.Fixed in 1.7.8-0.20260416142831-51806c22c575 - Upgrade
Upgrade
aws-efs-csi-driverto a version that resolves this vulnerability.Fixed in v3.0.1 - Compensating control
Restrict PersistentVolume and StorageClass creation to cluster administrators using Kubernetes RBAC, preventing untrusted users from supplying arbitrary field values.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-6437?
CVE-2026-6437 is considered a high severity vulnerability due to the potential for remote authenticated users to inject arbitrary mount options.
How do I fix CVE-2026-6437?
To fix CVE-2026-6437, upgrade the AWS EFS CSI Driver to version 3.0.1 or later.
Who is affected by CVE-2026-6437?
CVE-2026-6437 affects users with PersistentVolume creation permissions using AWS EFS CSI Driver versions prior to 3.0.1.
What types of attacks are possible with CVE-2026-6437?
CVE-2026-6437 may allow attackers to manipulate volume mount options potentially leading to privilege escalation or system instability.
Is there a workaround for CVE-2026-6437 before upgrading?
A recommended workaround for CVE-2026-6437 is to restrict PersistentVolume creation permissions to trusted users until an upgrade can be conducted.