CVE-2026-21751: HCL Hive Information Disclosure Vulnerability

CVE-2026-21751 Overview

CVE-2026-21751 affects HCL Hive due to a cryptographic primitive with a risky implementation. The weakness falls under [CWE-1240], which describes the use of a cryptographic algorithm or primitive with insecure properties. An attacker who compromises a single internal component can pivot laterally or extract widely reused credentials across the environment. The flaw is remotely reachable and requires no authentication, though exploitation is characterized as high complexity.

Critical Impact

A breach of one internal Hive component can cascade into widespread credential leakage and unauthorized lateral movement across trust boundaries.

Affected Products

• HCL Hive (specific versions not enumerated in the NVD entry)
• Refer to the HCL Software Knowledge Base Article for version details

Discovery Timeline

• 2026-08-24 - CVE-2026-21751 published to NVD
• 2026-08-24 - Last updated in NVD database

Technical Details for CVE-2026-21751

Vulnerability Analysis

HCL Hive implements a cryptographic primitive in a manner that reduces the isolation between internal components. The design reuses cryptographic material or applies a primitive in a way that binds the security of multiple components to a single secret or scheme. When one component is breached, the attacker inherits cryptographic trust that should have been scoped to that component alone.

The practical result is credential leakage at scale. Shared keys, tokens, or derived secrets exposed on one host translate into authenticated access on peer components. Attackers can then move laterally without triggering credential-guessing defenses because the material is already valid.

The issue is a design-level cryptographic weakness rather than a memory-safety bug. It cannot be mitigated by input sanitization or web-tier controls alone and requires vendor-supplied changes to key management and primitive selection.

Root Cause

The root cause is a risky implementation of a cryptographic primitive [CWE-1240]. Typical instances of this weakness include reusing a single symmetric key across components, deriving keys from predictable inputs, or applying a primitive outside its security assumptions. HCL has not published low-level details in the public advisory.

Attack Vector

The attack path is network-adjacent to the Hive deployment. An attacker must first compromise or gain access to one internal component. Once positioned, the attacker extracts cryptographic material and reuses it against peer components. High attack complexity reflects the prerequisite foothold and the need to locate and repurpose the shared material.

No public exploitation code or proof-of-concept is available at the time of publication. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Detection Methods for CVE-2026-21751

Indicators of Compromise

• Reuse of the same authentication token or key material observed across multiple Hive components within a short window
• Successful authentications between internal Hive components originating from unexpected source hosts
• Access to cryptographic key stores or configuration files containing shared secrets on any Hive host
• Sudden lateral connections from a single compromised component to peers on internal management ports

Detection Strategies

• Baseline the normal inter-component authentication pattern within Hive and alert on deviations in source, timing, or key identifier
• Monitor file and process access to key material paths documented in the HCL knowledge base article
• Correlate authentication events across Hive components to identify a single credential validating on multiple hosts in rapid succession

Monitoring Recommendations

• Forward Hive component authentication and audit logs to a centralized analytics platform for cross-host correlation
• Track process execution and file access on hosts that store cryptographic material used by Hive
• Alert on outbound connections from Hive components to unexpected internal or external destinations

How to Mitigate CVE-2026-21751

Immediate Actions Required

• Review the HCL Software Knowledge Base Article and apply the vendor-supplied fix on all Hive components
• Rotate any cryptographic keys, tokens, and shared secrets used by Hive after patching
• Restrict network reachability between Hive components and the rest of the environment to reduce blast radius if a component is breached
• Audit host and process access to key material and remove unnecessary privileges

Patch Information

HCL has published remediation guidance in KB0131731. Administrators should consult the article for fixed versions and required configuration steps, then apply the update across every Hive component in the deployment.

Workarounds

• Segment Hive components on dedicated network zones with strict east-west controls until the patch is applied
• Enforce host-based access controls on files that contain cryptographic material
• Increase logging verbosity for authentication and key-access events to shorten detection time during the exposure window