CVE-2026-90456: Inventory Management Auth Bypass Vulnerability

CVE-2026-90456 Overview

CVE-2026-90456 documents a hardcoded credentials weakness [CWE-1392] in a bundled inventory-management component distributed as part of an industrial control system deployment. The component ships with an example environment-configuration file containing a fixed, publicly-known administrative password. Operators who copy the example file into active configuration without running the setup routine that regenerates credentials leave the administrative interface exposed. Any attacker aware of the default value can authenticate remotely over the network. CISA published the issue in ICS Advisory ICSA-26-254-01.

Critical Impact

Remote, unauthenticated attackers can log in with the publicly-known default administrator password and gain full control of the inventory-management component.

Affected Products

• Inventory-management component referenced in CISA ICS Advisory ICSA-26-254-01
• Deployments that copied the shipped example environment-configuration file into production
• Installations where the credential-regeneration setup routine was not executed

Discovery Timeline

• 2026-09-11 - CVE-2026-90456 published to the National Vulnerability Database
• 2026-09-18 - Last updated in NVD database

Technical Details for CVE-2026-90456

Vulnerability Analysis

The vulnerability arises from a use of default credentials pattern classified under [CWE-1392]. The bundled inventory-management component ships an example environment-configuration file that defines an administrative password as a static, documented value. This file is intended as a template. A first-run setup routine is expected to overwrite the placeholder with a unique secret before the service is exposed.

When deployments skip the setup routine and promote the example file into active use, the administrative account retains the shipped value. That value is publicly documented, so knowledge of the product is sufficient to derive it. The administrative interface listens on the network, so no local access, user interaction, or prior privilege is required to exploit the condition.

Successful authentication grants full administrative control of the component, which typically includes read and write access to inventory records, user management, and integration endpoints connected to upstream operational technology systems.

Root Cause

The root cause is the distribution of a hardcoded, publicly-known credential inside a template configuration file, combined with a deployment workflow that does not enforce credential rotation before the service becomes reachable. Operators unaware of the setup routine treat the example file as production-ready.

Attack Vector

An attacker locates an exposed instance of the inventory-management component and submits the default administrator credentials to its login endpoint. Authentication succeeds and the attacker inherits administrative privileges. No exploit code is required, and no CISA KEV entry currently lists this CVE. Refer to CISA ICS Advisory ICSA-26-254-01 for the authoritative technical description.

No verified exploitation code is published. The vulnerability is triggered by
submitting the vendor-documented default administrator password to the
component's standard login interface.

Detection Methods for CVE-2026-90456

Indicators of Compromise

• Successful administrative logins to the inventory-management component from unexpected source addresses or outside normal operator working hours.
• Presence of the vendor-supplied example environment-configuration file in the active configuration path with unmodified credential values.
• Configuration changes, user additions, or integration endpoint modifications performed by the built-in administrator account without a corresponding change request.

Detection Strategies

• Compare the hash of the active environment-configuration file against the shipped example file to identify unmodified deployments.
• Query authentication logs for successful administrator sessions and correlate them against an allow-list of operator source networks.
• Scan reachable network segments for the component's administrative interface and attempt authentication with the documented default value in an authorized assessment.

Monitoring Recommendations

• Forward component authentication and audit logs to a centralized SIEM and alert on first-seen source addresses for the administrator account.
• Monitor for configuration export, user creation, and privilege-change events triggered by the built-in administrator.
• Baseline the component's outbound connections and alert on new integrations, which may indicate an attacker pivoting through the inventory service.

How to Mitigate CVE-2026-90456

Immediate Actions Required

• Rotate the administrative password on every deployment of the affected component and verify the new value is not the vendor default.
• Run the vendor setup routine that regenerates credentials, or manually replace the example file with a hardened configuration.
• Restrict network access to the administrative interface to trusted management networks until credential rotation is confirmed.
• Review authentication logs for prior successful administrator logins that predate the credential rotation.

Patch Information

Refer to CISA ICS Advisory ICSA-26-254-01 for vendor remediation guidance, fixed versions, and any updated deployment scripts that enforce credential regeneration during installation.

Workarounds

• Place the administrative interface behind a network segmentation boundary or VPN so it is unreachable from untrusted networks.
• Enforce a configuration management policy that blocks promotion of any file matching the shipped example environment-configuration template.
• Add a deployment pre-flight check that fails if the administrator password hash matches the vendor default.

# Configuration example: fail deployment if the default admin password is still in use
# Replace DEFAULT_HASH with the SHA-256 of the vendor-documented default value.
CURRENT_HASH=$(grep -E '^ADMIN_PASSWORD=' /etc/inventory/app.env \
  | cut -d= -f2- \
  | tr -d '"' \
  | sha256sum \
  | awk '{print $1}')

if [ "$CURRENT_HASH" = "DEFAULT_HASH" ]; then
  echo "ERROR: default administrative password detected. Rotate before deployment."
  exit 1
fi