CVE-2026-56581: HCL MyCloud Auth Bypass Vulnerability

CVE-2026-56581 Overview

CVE-2026-56581 affects HCL MyCloud version 10.8.1. The application fails to set the Path attribute on cookies, which may increase the risk of unauthorized access to session data or authentication tokens. The issue is categorized under [CWE-614], which covers sensitive cookie handling without proper protective attributes. HCL Technologies published a knowledge base article documenting the issue and remediation guidance.

Critical Impact
Missing cookie Path attribute may expose session identifiers or authentication tokens to unintended application paths, enabling potential cross-application cookie disclosure under specific conditions.

Affected Products

HCL MyCloud 10.8.1
Deployments using default cookie configuration
Session and authentication token cookies issued by MyCloud

Discovery Timeline

2026-07-21 - CVE-2026-56581 published to the National Vulnerability Database (NVD)
2026-07-22 - Last updated in NVD database

Technical Details for CVE-2026-56581

Vulnerability Analysis

The vulnerability stems from HCL MyCloud issuing cookies without an explicit Path attribute. When the Path attribute is absent, browsers apply a default scope based on the request URI. This behavior can broaden cookie visibility beyond the intended application scope. Cookies used for session tracking or authentication become accessible to other paths served from the same origin.

The issue is a configuration weakness rather than a memory or logic flaw. Exploitation requires network access, low privileges, user interaction, and specific conditions in the hosting environment. The confidentiality impact is limited, and there is no direct integrity or availability impact.

Root Cause

The root cause is missing enforcement of the Path cookie attribute within the HCL MyCloud application server response headers. Under [CWE-614] guidance, sensitive cookies should carry protective attributes such as Secure, HttpOnly, and a restrictive Path to constrain their scope. HCL MyCloud 10.8.1 issues cookies without setting Path, defaulting browser scoping behavior.

Attack Vector

An attacker who can host or influence content on a shared origin path may observe cookies that should have been scoped to the MyCloud application. Exploitation is network-based but requires user interaction and specific conditions to succeed. The vulnerability does not permit direct code execution or data modification. No public proof-of-concept exploit is available, and the issue is not listed on the CISA Known Exploited Vulnerabilities catalog.

No verified exploitation code is available for this configuration weakness. Refer to the HCL Software Knowledge Base Article for vendor technical details.

Detection Methods for CVE-2026-56581

Indicators of Compromise

HTTP Set-Cookie response headers from HCL MyCloud lacking a Path attribute
Session cookies transmitted on requests to unintended application paths on the same origin
Unexpected authentication token reuse observed in web server access logs

Detection Strategies

Inspect HTTP responses from HCL MyCloud endpoints and flag Set-Cookie headers that omit the Path directive
Compare deployed MyCloud version against 10.8.1 to identify systems in scope
Review web application firewall and reverse proxy logs for cookies being sent to non-application paths on the same host

Monitoring Recommendations

Enable HTTP header logging on reverse proxies fronting HCL MyCloud to capture Set-Cookie attributes
Monitor authentication token usage patterns for anomalies in request paths
Track vendor advisories from HCL for follow-up guidance referenced in KB0132381

How to Mitigate CVE-2026-56581

Immediate Actions Required

Review the HCL Software Knowledge Base Article for vendor-supplied remediation steps
Inventory HCL MyCloud deployments at version 10.8.1 and prioritize remediation on internet-facing instances
Restrict which applications share the same origin as HCL MyCloud to reduce cookie scope exposure

Patch Information

HCL Technologies documents remediation guidance in knowledge base article KB0132381. Administrators should follow the vendor instructions to apply the recommended configuration or update. Confirm that Set-Cookie headers issued by MyCloud include an explicit, restrictive Path attribute after remediation.

Workarounds

Configure the reverse proxy or web server fronting HCL MyCloud to rewrite Set-Cookie headers and add a restrictive Path attribute
Deploy HCL MyCloud on a dedicated hostname or subdomain to isolate cookies from other applications
Enforce Secure and HttpOnly cookie attributes alongside Path where supported by the deployment configuration

bash

# Example NGINX proxy_cookie_path directive to enforce cookie Path scope
location /mycloud/ {
    proxy_pass http://mycloud_backend/;
    proxy_cookie_path / "/mycloud/; Secure; HttpOnly";
}