Username enumeration via distinguishable authentication failures
Published Oct 13, 2026 · Updated Oct 13, 2026
Username enumeration in BusyBox httpd allows remote attackers to identify system accounts through authentication-failure behavior. The system-password authentication path handles nonexistent accounts differently from password verification, exposing account existence through failed authentication. Exposure requires non-default compile options or uncommon password-file states; the supplied source states that default builds with shadow-password support are unaffected and limits the impact to username enumeration.
Summary
What happened
Username enumeration in BusyBox httpd allows remote attackers to identify system accounts through authentication-failure behavior. The system-password authentication path handles nonexistent accounts differently from password verification, exposing account existence through failed authentication. Exposure requires non-default compile options or uncommon password-file states; the supplied source states that default builds with shadow-password support are unaffected and limits the impact to username enumeration.
The record
- CVE
- CVE-2026-88834
- Published
- Oct 13, 2026
- Updated
- Oct 13, 2026
- Vendor
- libuser Project
- Product
- Red Hat Hardened Images
- Classifications
- T1589
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 13, 2026CVE publishedPublication date reported by the CVE source.
- Oct 13, 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?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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