HCL BigFix Platform is affected by a user enumeration vulnerability which might allow an attacker, through careful system control and response time monitoring, to perform some level of user enumeration for the BigFix service.
CVE-2026-21840
LOWPre-NVD 3.13.1Trending — 3 sources updated this week
EchelonGraph scoreLOW confidence
This low-severity CVE scores 3.1 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: cna:hcl
3.1
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 3.1Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 3.1
- EG Score
- 3.1(low)
- EPSS
- 4.9%
- KEV
- Not listed
Published
July 14, 2026
Last Modified
July 15, 2026
References (1)
Vendor Advisories for CVE-2026-21840(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 4× in last 7d / 4× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-14 22:01 UTCEG score recompute
- 2026-07-14 22:00 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-21840?
CVE-2026-21840 is a low vulnerability published on July 14, 2026. HCL BigFix Platform is affected by a user enumeration vulnerability which might allow an attacker, through careful system control and response time monitoring, to perform some level of user enumeration for the BigFix service.
When was CVE-2026-21840 disclosed?
CVE-2026-21840 was first published in the National Vulnerability Database on July 14, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-21840 actively exploited?
CVE-2026-21840 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 4.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-21840?
CVE-2026-21840 has a CVSS v3 base score of 3.1 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-21840?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-21840, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-21840
Is Your Infrastructure Affected by CVE-2026-21840?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.