CVE-2026-21810: HCL BigFix Quantum Risk Analyzer Flaw

CVE-2026-21810 is an information disclosure vulnerability in HCL BigFix Quantum Risk Analyzer caused by hardcoded resources and lack of binary integrity. Attackers can obtain sensitive data or modify binaries. This article covers technical details, impact assessment, affected versions, and mitigation strategies.

CVE-2026-21810 Overview

CVE-2026-21810 affects HCL BigFix Quantum Risk Analyzer. The product contains a hardcoded external resource reference and lacks binary integrity verification. An authenticated local attacker with high privileges can exploit these weaknesses to obtain sensitive information or modify the binary. The vulnerability is tracked under CWE-494: Download of Code Without Integrity Check. HCL Software published a knowledge base article describing the issue and remediation guidance.

Critical Impact
A local attacker with high privileges can tamper with the BigFix Quantum Risk Analyzer binary, undermining the integrity of downstream risk analysis output.

Affected Products

HCL BigFix Quantum Risk Analyzer

Discovery Timeline

2026-08-26 - CVE-2026-21810 published to NVD
2026-08-26 - Last updated in NVD database

Technical Details for CVE-2026-21810

Vulnerability Analysis

HCL BigFix Quantum Risk Analyzer references an external resource through a hardcoded location. The product does not verify the integrity of the binary it consumes at that location. An attacker who can reach the referenced path or modify the binary can substitute or alter the code that the application trusts.

Because the external reference is fixed in the product, defenders cannot easily reroute it to a controlled location. The absence of integrity validation means the modified binary executes without triggering a signature or hash mismatch. The CVSS vector indicates a local attack path requiring high privileges, with impact limited to integrity.

Root Cause

The root cause is twofold. First, the product hardcodes an external resource reference, removing the ability to authenticate the source at runtime. Second, the product does not perform cryptographic signature validation or hash checking on the referenced binary. Together, these weaknesses map directly to CWE-494, which covers code downloaded or loaded without integrity verification.

Attack Vector

Exploitation requires local access and high privileges on the host running HCL BigFix Quantum Risk Analyzer. An attacker with these prerequisites can replace or modify the referenced binary on disk. When the analyzer loads the binary, it executes the attacker-supplied version without detecting the change. The vulnerability does not require user interaction. Confidentiality and availability impacts are not scored, but integrity impact is high because the tampered binary can produce misleading risk analysis results or execute attacker-controlled logic within the analyzer context.

The vulnerability manifests in the code path that resolves and loads the hardcoded external resource. See the HCL Software Knowledge Base Article for vendor-specific technical details.

Detection Methods for CVE-2026-21810

Indicators of Compromise

Unexpected modification timestamps or hash changes on binaries loaded by HCL BigFix Quantum Risk Analyzer
Writes to the hardcoded resource path by processes other than the BigFix installer or update service
Anomalous risk analysis output that diverges from historical baselines on the same asset

Detection Strategies

Baseline the cryptographic hashes of all BigFix Quantum Risk Analyzer binaries after a clean install and compare periodically
Monitor file integrity on the hardcoded external resource location referenced by the analyzer
Correlate local privilege elevation events on BigFix hosts with subsequent file writes to analyzer resource paths

Monitoring Recommendations

Enable file integrity monitoring on the BigFix Quantum Risk Analyzer installation directory and its referenced external resources
Audit process execution for unsigned or newly introduced binaries running under the BigFix service account
Review privileged local logon events on hosts running BigFix components and alert on rare or off-hours activity

How to Mitigate CVE-2026-21810

Immediate Actions Required

Restrict local administrative access to hosts running HCL BigFix Quantum Risk Analyzer to a minimal set of accounts
Apply the vendor-provided remediation described in the HCL Software Knowledge Base Article
Enforce file integrity monitoring on the analyzer binary and its referenced external resource path

Patch Information

HCL Software has published remediation guidance in Knowledge Base Article KB0133289. Administrators should follow the vendor instructions to update HCL BigFix Quantum Risk Analyzer to a fixed version and validate that the referenced external resource is verified through integrity checks after the update.

Workarounds

Limit filesystem permissions on the hardcoded resource path so that only trusted service accounts can write to it
Apply operating system-level application allowlisting to prevent execution of unsigned binaries under the BigFix service context
Segment BigFix management hosts from general-purpose workstations to reduce the pool of accounts with local access

bash

# Example: verify binary hash against a known-good baseline before analyzer startup
sha256sum /path/to/bigfix/quantum-risk-analyzer.bin | \
  diff - /secure/baselines/quantum-risk-analyzer.sha256