CVE-2026-56580 Overview
CVE-2026-56580 affects HCL MyCloud due to the use of a component with known vulnerabilities in its Internet Information Services (IIS) Server dependency [CWE-1104]. The flaw allows attackers with high privileges to exploit publicly disclosed weaknesses in the bundled IIS component and obtain limited confidential information from the affected system. Exploitation requires network access and high attack complexity, limiting the practical risk. No integrity or availability impact is associated with this issue. HCL Software published a Knowledge Base advisory describing remediation steps for affected MyCloud deployments.
Critical Impact
Authenticated attackers may exploit outdated IIS Server components bundled with HCL MyCloud to disclose limited confidential information.
Affected Products
- HCL MyCloud
- Bundled Microsoft Internet Information Services (IIS) Server component
- Deployments referenced in the HCL Software Knowledge Base Article
Discovery Timeline
- 2026-07-21 - CVE-2026-56580 published to NVD
- 2026-07-22 - Last updated in NVD database
Technical Details for CVE-2026-56580
Vulnerability Analysis
CVE-2026-56580 is categorized under [CWE-1104]: Use of Unmaintained Third Party Components. HCL MyCloud ships with a version of Microsoft IIS Server that contains publicly disclosed vulnerabilities. Attackers who already hold high privileges on the target can leverage those known weaknesses through the network-facing IIS surface. Successful exploitation yields limited confidentiality impact without affecting integrity or availability. The high attack complexity indicates that non-default conditions must be satisfied before an attacker can reliably trigger the underlying weakness.
Root Cause
The root cause is dependency hygiene. HCL MyCloud bundles or relies on an IIS Server component that has not been updated to a patched, supported version. When third-party components remain at vulnerable revisions, the parent product inherits every publicly known flaw of the embedded component. This is a supply chain and lifecycle management defect rather than a coding error introduced in HCL MyCloud itself.
Attack Vector
The attack vector is Network. An authenticated attacker with high privileges reaches the exposed IIS endpoint over the network and invokes functionality that maps to a known vulnerability in the outdated IIS component. Because the scope is unchanged and only confidentiality is affected, the practical outcome is disclosure of limited configuration or runtime information rather than full compromise of the host.
No verified proof-of-concept code is published for CVE-2026-56580. Refer to the HCL Software Knowledge Base Article for vendor-specific technical details.
Detection Methods for CVE-2026-56580
Indicators of Compromise
- Unexpected authenticated HTTP requests to administrative IIS endpoints on HCL MyCloud hosts.
- IIS worker process (w3wp.exe) spawning unusual child processes or reading sensitive configuration files.
- Access to IIS metabase or applicationHost.config outside routine administrative windows.
Detection Strategies
- Inventory IIS versions and modules on all HCL MyCloud servers and compare against Microsoft's supported and patched builds.
- Correlate authenticated requests from high-privilege accounts with IIS request logs to surface abuse of privileged sessions.
- Enable IIS Enhanced Logging and forward events to a centralized analytics platform for behavioral baselining.
Monitoring Recommendations
- Monitor for privilege changes and administrative logons on hosts running HCL MyCloud.
- Alert on modifications to IIS configuration files, application pools, and installed modules.
- Track outbound data volumes from IIS worker processes to identify potential information disclosure.
How to Mitigate CVE-2026-56580
Immediate Actions Required
- Review the HCL Software Knowledge Base Article and apply the vendor-recommended remediation.
- Update the underlying IIS Server component to a currently supported and fully patched Microsoft release.
- Restrict administrative access to HCL MyCloud to a minimal set of accounts and enforce multi-factor authentication.
Patch Information
HCL Software has published remediation guidance in KB0132381. Administrators should follow the vendor advisory to update or reconfigure the bundled IIS Server component and validate that all Microsoft security updates for IIS are installed on the underlying Windows Server.
Workarounds
- Limit network exposure of the IIS endpoints on HCL MyCloud hosts to trusted management networks only.
- Disable IIS modules and features that are not required by HCL MyCloud to reduce the attack surface.
- Enforce strict role-based access control so that only vetted administrators hold the high privileges required for exploitation.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
