aws-efs-csi-driver: Unverified Ownership
CVE-2026-85781 is a high-severity unverified ownership vulnerability in aws-efs-csi-driver from AWS, with a CVSS 3.1 base score of 8.7 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected aws-efs-csi-driver versions: 3.4.0 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.44% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of aws-efs-csi-driver you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on aws.amazon.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| AWS | aws-efs-csi-driver | 3.4.0 and earlier | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:H. Scored by CNA.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 5.1 | Medium | CNA |
| CVSS 3.1 | 8.7 | High | CNA |
Official description
Unverified ownership of a storage access point in the volume deletion component of the Amazon EFS CSI Driver before v3.4.1 might allow an authenticated Kubernetes user with PersistentVolume creation privileges to cause recursive deletion of directories on an EFS filesystem they are not authorized to access, via a crafted PersistentVolume volumeHandle that pairs an access point from one filesystem with a different target filesystem. To remediate this issue, users should upgrade to version v3.4.1.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Unverified Ownership
The product does not properly verify that a critical resource is owned by the proper entity.
How developers prevent this class of flaw
- Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Unverified Ownership vulnerabilities
- 7.0 High severity
- 7.5 High severity
- 7.5 High severity
- 8.1 High severity
- 7.8 High severity
- 7.2 High severity
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