# CVE-2026-21807 — HCLSoftware BigFix Quantum Risk Analyzer

> As of 2026-08-27, CVE-2026-21807 is a LOW-severity vulnerability in HCLSoftware BigFix Quantum Risk Analyzer, CVSS v3.1 3.9, EPSS 0.0% (57.2th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-21807 as of 2026-08-27; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-08-27

## What is CVE-2026-21807?

HCL BigFix Quantum Risk Analyzer binary lacks several critical, industry-standard hardening protections that could allow an attacker to cause a stack-based buffer overflow.

The record classifies CVE-2026-21807 under weakness class [CWE-121](https://intel.threadlinqs.com/cwe/CWE-121). Its CVSS v3 base vector states that the flaw requires local access to the host, needs high-privilege credentials, needs no user interaction. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 40 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 3.9 — LOW (`CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:L`)
- **EPSS (FIRST):** 0.0% probability of exploitation in the next 30 days, higher than 57.2% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.2/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-08-26, last modified 2026-08-27

## Is CVE-2026-21807 being exploited?

It currently carries a trending score of 44 in the Threadlinqs vulnerability feed.

## Affected products and versions

- **HCLSoftware**: BigFix Quantum Risk Analyzer

## How to fix CVE-2026-21807

No vendor patch reference has been recorded for CVE-2026-21807 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-21807

No threat campaign in the Threadlinqs corpus currently references CVE-2026-21807, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on 2026-08-27. This product uses the NVD API but is not endorsed or certified by the NVD.

**Other references**

- [support.hcl-software.com](https://support.hcl-software.com/csm?id=kb_article&sysparm_article=KB0133289)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-21807
Full detection coverage and IOCs for threats exploiting CVE-2026-21807 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp