# CVE-2026-85781: Amazon EFS CSI Driver insufficient access point ownership validation

Source: https://junglewise.ai/threats/cve-2026-85781-amazon-efs-csi-driver-insufficient-access-point-ownership  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-04. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-85781 · Severity: high · CVSS 8.7 · Published 2026-09-04

The Amazon EFS CSI Driver is a Kubernetes storage plugin that enables containerized applications to use Amazon EFS file systems. A vulnerability in its volume-deletion logic allows authenticated Kubernetes users with permission to create volumes to exploit a non-default configuration and cause the driver to recursively delete directories from EFS file systems they are not authorized to access, potentially resulting in data loss.

Technologies: [Amazon AWS](https://junglewise.ai/threats/technologies/aws), [Amazon EFS CSI Driver](https://junglewise.ai/threats/technologies/efs-csi-driver). Vendors: [Amazon](https://junglewise.ai/threats/vendors/amazon).

## Quick answers

**Is CVE-2026-85781 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-85781 being exploited in the wild.

**How severe is CVE-2026-85781?** High severity, with a CVSS score of 8.7, published 4 September 2026.

**Which products and versions are affected?** Amazon EFS CSI Driver <=3.4.0.

**Is there a fix for CVE-2026-85781?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-85781 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-85781?** Check whether you run Amazon AWS or Amazon EFS CSI Driver at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

CVE-2026-85781 is an insufficient validation vulnerability in the Amazon EFS CSI Driver's volume-deletion controller logic. When the non-default --delete-access-point-root-dir=true flag is enabled, the controller fails to verify that the EFS access point referenced in a PersistentVolume's volume handle actually belongs to the file system also referenced in that same volume handle. An authenticated Kubernetes user with create/delete PersistentVolume permissions can craft a malicious volume handle containing a valid access point from a different EFS file system, causing the controller to recursively delete directories from that unauthorized file system during volume deletion. The vulnerability requires specific configuration (the non-default flag must be set) and Kubernetes API access, but does not affect the underlying Amazon EFS access control mechanisms. Patches are expected in versions after 3.4.0.

## Affected products

- Amazon EFS CSI Driver <=3.4.0

## Timeline

- 2026-09-09: disclosed
- 2026-09-04: advisory: AWS Security Bulletin 2026-099-AWS published

## References

- [https://aws.amazon.com/security/security-bulletins/rss/2026-099-aws/](https://aws.amazon.com/security/security-bulletins/rss/2026-099-aws/)

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