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PatchSiren cyber security CVE debrief

CVE-2026-6437 Amazon CVE debrief

A vulnerability in the AWS EFS CSI Driver before v3.0.1 allows remote authenticated users with PersistentVolume creation permissions to inject arbitrary mount options via comma injection in the volume handling component. The issue stems from improper neutralization of argument delimiters (CWE-88), which could lead to integrity impacts on the system cluster. The vulnerability was published on April 17, 2026, and last modified on June 1, 2026. Amazon has released version v3.0.1 to address this issue.

Vendor
Amazon
Product
AWS EFS CSI Driver
CVSS
MEDIUM 6.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-04-17
Original CVE updated
2026-06-01
Advisory published
2026-04-17
Advisory updated
2026-06-01

Who should care

Organizations running AWS EFS CSI Driver versions prior to v3.0.1 in Kubernetes environments, particularly those with multi-tenant clusters where PersistentVolume creation permissions may be granted to non-administrative users. Platform engineering teams, Kubernetes cluster administrators, and security teams responsible for container storage security should prioritize this update.

Technical summary

The AWS EFS CSI Driver's volume handling component fails to properly neutralize argument delimiters, specifically commas, in mount option processing. An authenticated attacker with PersistentVolume creation permissions can inject additional mount options by including comma characters in input fields that are subsequently passed to mount commands. This could allow manipulation of filesystem mount behavior, potentially leading to unauthorized data access or integrity violations within the Kubernetes cluster. The vulnerability is addressed in version v3.0.1 through proper input sanitization.

Defensive priority

medium

Recommended defensive actions

  • Upgrade aws-efs-csi-driver to version v3.0.1 or later
  • Review and restrict PersistentVolume creation permissions to only trusted principals
  • Audit existing PersistentVolume configurations for unexpected mount options
  • Monitor for anomalous mount option usage in EFS CSI Driver deployments
  • Apply principle of least privilege for Kubernetes RBAC roles related to volume management

Evidence notes

The vulnerability is classified as CWE-88 (Improper Neutralization of Argument Delimiters in a Command). The CVSS 4.0 vector indicates network attack vector with low attack complexity, requiring high privileges, with high integrity impact to the system cluster. The affected product is the Amazon EFS CSI Driver for Kubernetes, with versions prior to 3.0.1 being vulnerable.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-6437 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-6437

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-6437 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-6437

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://aws.amazon.com/security/security-bulletins/2026-016-aws/

    ff89ba41-3aa1-4d27-914a-91399e9639e5 - Vendor Advisory

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://github.com/kubernetes-sigs/aws-efs-csi-driver/releases/tag/v3.0.1

    ff89ba41-3aa1-4d27-914a-91399e9639e5 - Release Notes

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://github.com/kubernetes-sigs/aws-efs-csi-driver/security/advisories/GHSA-mph4-q2vm-w2pw

    ff89ba41-3aa1-4d27-914a-91399e9639e5 - Vendor Advisory

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.