CVE-2026-21758 Overview
CVE-2026-21758 is an information disclosure vulnerability affecting HCL Hive. An attacker can leverage the flaw to gather sensitive information about the host environment. The weakness is classified under [CWE-200], Exposure of Sensitive Information to an Unauthorized Actor. Exploitation occurs over the network without authentication or user interaction, though attack complexity is high. Confidentiality impact is limited, and there is no impact to integrity or availability.
Critical Impact
An unauthenticated remote attacker can retrieve limited host environment details from HCL Hive, aiding reconnaissance for follow-on attacks.
Affected Products
- HCL Hive (version details not disclosed in NVD entry)
Discovery Timeline
- 2026-08-25 - CVE-2026-21758 published to NVD
- 2026-08-25 - Last updated in NVD database
Technical Details for CVE-2026-21758
Vulnerability Analysis
HCL Hive exposes sensitive host environment information to unauthorized network callers. The flaw maps to [CWE-200], where the application returns data that should remain internal to the deployment. The disclosed information can include host configuration details useful to an attacker profiling the target.
The issue is reachable over the network without authentication or user interaction. However, exploitation requires specific conditions that raise attack complexity, according to the vendor scoring. The impact is limited to a partial loss of confidentiality; the vulnerability does not allow modification of data or disruption of service.
Exposed environment metadata frequently serves as an early reconnaissance stage. Attackers use such data to fingerprint software versions, identify internal hostnames, or map trust relationships before selecting a follow-on exploit.
Root Cause
The root cause is improper restriction of sensitive information returned by HCL Hive. The application does not sufficiently filter host environment details before responding to network requests. HCL has not published implementation-level detail in the public advisory.
Attack Vector
The attack vector is network based. A remote attacker sends crafted requests to an exposed HCL Hive instance and parses the response for environment data. No credentials or user interaction are required. Technical details of the request pattern are not disclosed in the vendor knowledge base article at the time of publication.
Refer to the HCL Software Knowledge Base Article for vendor-provided technical context.
Detection Methods for CVE-2026-21758
Indicators of Compromise
- Anomalous unauthenticated requests to HCL Hive endpoints that return configuration or environment metadata.
- Repeated probing from a single source targeting Hive service ports, consistent with reconnaissance activity.
- Outbound responses from Hive containing internal hostnames, paths, or version strings to untrusted networks.
Detection Strategies
- Enable verbose application and access logging on HCL Hive services to capture response payloads for review.
- Correlate web application firewall (WAF) logs with Hive access logs to identify unauthenticated probing patterns.
- Baseline typical Hive request volumes and alert on statistical deviations that suggest scripted enumeration.
Monitoring Recommendations
- Monitor network traffic to Hive services from external or untrusted network segments.
- Track responses that include environment identifiers, credentials, or configuration keys leaving the application tier.
- Review authentication logs for missing sessions on endpoints that should require login.
How to Mitigate CVE-2026-21758
Immediate Actions Required
- Consult the HCL Software Knowledge Base Article for the vendor-supplied fix and apply it to all HCL Hive instances.
- Restrict network exposure of HCL Hive management and API endpoints to trusted segments only.
- Audit recent Hive access logs for unauthenticated requests that returned environment or configuration data.
Patch Information
HCL has published guidance for CVE-2026-21758 in knowledge base article KB0133342. Administrators should follow the vendor advisory for the specific fixed builds and upgrade paths. NVD does not enumerate affected version ranges in the current entry.
Workarounds
- Place HCL Hive behind a reverse proxy or WAF that enforces authentication before requests reach the service.
- Apply network access control lists (ACLs) to limit Hive connectivity to known administrative subnets.
- Remove verbose error and environment output from responses where configuration options permit.
# Example: restrict inbound access to HCL Hive to a management subnet
iptables -A INPUT -p tcp --dport <hive_port> -s 10.10.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport <hive_port> -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
