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Full vulnerability report · 2026
CVE-2026-85781High confidence

Unverified access point ownership in Amazon EFS CSI Driver

aws · aws-efs-csi-driver

5.1MediumCVSS 4.0
Recommended action
Patch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 0.44% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs aws aws-efs-csi-driver and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Cross-source reconciliation

Remediation availability differs by product scope

Verified remediation exists for at least one product or source, but 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2026-85781 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitygithub.com/kubernetes-sigs/aws-efs-csi-driver: Amazon EFS CSI Driver: Unauthorized directory deletion via unverified access point ownership
2 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • openshift4/ose-aws-efs-csi-driver-container-rhel8 as a component of Red Hat OpenShift Container Platform 4
  • openshift4/ose-aws-efs-csi-driver-container-rhel9 as a component of Red Hat OpenShift Container Platform 4
Summary
A flaw was found in the Amazon EFS Container Storage Interface (CSI) Driver. When the controller is configured with the non-default --delete-access-point-root-dir=true option, it does not verify that the EFS access point referenced by a PersistentVolume's volumeHandle belongs to the file system referenced by that same volumeHandle. An authenticated Kubernetes user with PersistentVolume creation privileges could exploit this vulnerability. By crafting a PersistentVolume volumeHandle that pairs an access point from one filesystem with a different target filesystem, an attacker could cause recursive deletion of directories on an Amazon Elastic File System (EFS) filesystem they are not authorized to access. This could lead to a denial of service or data loss.
Remediation
Ensure the EFS CSI Driver controller is configured with --delete-access-point-root-dir=false (the default setting). Deployments that have not explicitly enabled this flag are not affected by this vulnerability. If the flag is enabled and required for your workflow, restrict PersistentVolume creation privileges to trusted administrators using Kubernetes RBAC.
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-71692

No EUVD known-exploited evidence

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.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
5.1 · CVSS 4.0
Advisory evidence
No linked advisory details stored yet
Recommended actionPatch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
01

What, why and how

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.

What

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.

Why

The product does not properly verify that a critical resource is owned by the proper entity.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

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.

Why

The product does not properly verify that a critical resource is owned by the proper entity.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Unverified Ownership → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
High: elevated access is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-283 ↗

CWE-283: Unverified Ownership. The product does not properly verify that a critical resource is owned by the proper entity.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:H/SA:H

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATPresentAttack requirements: A particular deployment or execution condition must be present.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UINoneUser interaction: No action by another user is required.VCNoneVulnerable-system confidentiality: No direct loss is represented by this metric.VINoneVulnerable-system integrity: No direct loss is represented by this metric.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SIHighSubsequent-system integrity: A successful attack can cause a major loss.SAHighSubsequent-system availability: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkCWE-283
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-71692Official EUVD mapping

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.

Official EUVD record ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260909Security Bulletin 9 Sep 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 9 Sep 2026, published on 9 September 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix availability varies by product
Affected
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
Workaround
Ensure the EFS CSI Driver controller is configured with --delete-access-point-root-dir=false (the default setting). Deployments that have not explicitly enabled this flag are not affected by this vulnerability. If the flag is enabled and required for your workflow, restrict PersistentVolume creation privileges to trusted administrators using Kubernetes RBAC.
04

Evidence and provenance

Published 4 Sept 2026 · Last source change 4 Sept 2026, 19:28 UTC · CWE-283 · Unverified Ownership

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-09-06
European sourceENISA EUVD · EUVD-2026-71692
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD awaiting enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. ENISA EUVD mappingEUVD-2026-71692 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2026-71692"}
    ENISA EUVD ↗
  2. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2026-71692↗Vendor CSAF · Red Hat Product Security↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
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