Authenticated user enumeration via response timing
Published Jul 14, 2026 · Updated Jul 14, 2026
User enumeration in HCL BigFix Platform 10.0.0 through 10.0.15 and 11.0.0 through 11.0.5 allows remote authenticated users to identify service users. HCL has not published the affected request handler; the BigFix service produces observable response-time differences for tested user identities. A valid low-privilege account and controlled, repeated timing measurements are required, and the bounded consequence is disclosure of which service users exist.
Summary
What happened
User enumeration in HCL BigFix Platform 10.0.0 through 10.0.15 and 11.0.0 through 11.0.5 allows remote authenticated users to identify service users. HCL has not published the affected request handler; the BigFix service produces observable response-time differences for tested user identities. A valid low-privilege account and controlled, repeated timing measurements are required, and the bounded consequence is disclosure of which service users exist.
The record
- CVE
- CVE-2026-21840
- Published
- Jul 14, 2026
- Updated
- Jul 14, 2026
- Vendor
- HCLSoftware
- Product
- HCL BigFix Platform
- Classifications
- CWE-208, T1087
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 14, 2026CVE publishedPublication date reported by the CVE source.
- Jul 14, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.0 - 10.0.15, 11.0.0 - 11.0.5
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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