CVE-2026-40636: Dell Elastic Cloud Storage Auth Bypass

CVE-2026-40636 Overview

CVE-2026-40636 is a hard-coded credentials vulnerability [CWE-798] affecting Dell Elastic Cloud Storage (ECS) versions 3.8.1.0 through 3.8.1.7 and Dell ObjectScale versions prior to 4.3.0.0. The flaw allows an unauthenticated attacker with local access to use embedded credentials to access the underlying filesystem. Dell disclosed the issue in advisory DSA-2026-047 alongside other ECS and ObjectScale vulnerabilities. The vulnerability carries a CVSS 3.1 base score of 7.8 with high impacts to confidentiality, integrity, and availability.

Critical Impact

An attacker with local access can leverage hard-coded credentials to read, modify, or destroy data on the ECS or ObjectScale node filesystem.

Affected Products

• Dell Elastic Cloud Storage (ECS) versions 3.8.1.0 through 3.8.1.7
• Dell ObjectScale versions prior to 4.3.0.0
• Object storage appliances and software deployments built on the affected ECS and ObjectScale releases

Discovery Timeline

• 2026-05-11 - CVE-2026-40636 published to NVD
• 2026-05-12 - Last updated in NVD database

Technical Details for CVE-2026-40636

Vulnerability Analysis

Dell ECS and ObjectScale are enterprise object storage platforms exposing S3-compatible APIs over distributed storage nodes. The affected releases ship with hard-coded credentials embedded in product components. An attacker that reaches the local node — for example, through a low-privileged shell, a co-located workload, or a compromised management interface — can authenticate using these static credentials. Successful authentication grants filesystem access on the storage node, allowing the attacker to read configuration files, exfiltrate stored object data, tamper with system binaries, or disrupt the storage service. The CWE-798 classification reflects the underlying weakness: credentials are static across deployments and cannot be rotated by customers without a vendor patch.

Root Cause

The root cause is the inclusion of static authentication material inside ECS and ObjectScale binaries or configuration. Because the secret is identical across affected installations, knowledge of the credential — obtained through reverse engineering or shared between attackers — bypasses normal identity controls on every vulnerable node.

Attack Vector

Exploitation requires local access (AV:L) and low privileges (PR:L), but no user interaction. A threat actor with a foothold on an ECS or ObjectScale host, or on an adjacent system able to reach local interfaces, supplies the embedded credentials to a service that accepts them. The service authorizes filesystem operations, producing high-impact confidentiality, integrity, and availability outcomes. No public proof-of-concept or in-the-wild exploitation has been reported, and the EPSS score is low. See the Dell Security Update DSA-2026-047 for vendor technical detail.

No verified public proof-of-concept code is available for CVE-2026-40636.
Refer to Dell DSA-2026-047 for component-level technical detail.

Detection Methods for CVE-2026-40636

Indicators of Compromise

• Authentication events on ECS or ObjectScale nodes from accounts that are not part of the customer identity store or documented service accounts.
• Unexpected reads of /etc, key material directories, or object data paths on storage nodes by service accounts associated with internal components.
• New or unscheduled local shell sessions on ECS or ObjectScale appliances, particularly outside maintenance windows.

Detection Strategies

• Inventory ECS deployments and flag any node running versions 3.8.1.0 through 3.8.1.7, and ObjectScale nodes running versions earlier than 4.3.0.0.
• Correlate local logon and sudo events on storage nodes with change-management records to identify unauthorized local access.
• Hunt for processes spawned by ECS or ObjectScale service users that perform broad filesystem reads or writes outside their normal operational profile.

Monitoring Recommendations

• Forward node-level audit logs, ECS management logs, and ObjectScale platform logs to a central SIEM for retention and correlation.
• Alert on failed and successful authentications to internal service endpoints from unexpected source addresses on the storage management network.
• Baseline normal file-access patterns for ECS and ObjectScale service accounts and alert on deviations.

How to Mitigate CVE-2026-40636

Immediate Actions Required

• Apply the fixes referenced in DSA-2026-047 and upgrade ECS beyond 3.8.1.7 and ObjectScale to 4.3.0.0 or later as published by Dell.
• Restrict local and management-plane access to ECS and ObjectScale nodes to a minimum set of administrators using jump hosts and MFA.
• Audit existing accounts on storage nodes and remove or disable any non-required local access paths.

Patch Information

Dell has published remediation guidance in Dell Security Update DSA-2026-047. Upgrade Dell ECS to a version later than 3.8.1.7 and Dell ObjectScale to 4.3.0.0 or later. Follow Dell's documented upgrade procedure for the deployment topology in use.

Workarounds

• Place ECS and ObjectScale management interfaces on an isolated administrative network reachable only via bastion hosts.
• Enforce strict network segmentation between tenant workloads and storage node operating systems to reduce local-access exposure.
• Increase logging verbosity on storage nodes and monitor for unexpected authentications until patches are deployed.

# Identify affected Dell ECS / ObjectScale versions on managed hosts
# (Adapt to your inventory tooling; this is illustrative.)
for host in $(cat ecs_hosts.txt); do
  ssh "$host" 'cat /etc/ecs-release 2>/dev/null; cat /etc/objectscale-release 2>/dev/null'
done