Account discovery via distinguishable username-check responses
Published May 23, 2026 · Updated May 23, 2026
Username enumeration in UserSpice 4.3.24 allows remote attackers to identify valid accounts through crafted POST requests. The existingUsernameCheck.php endpoint accepts an unauthenticated username, checks whether it exists, and returns the distinguishable text 'taken' when a match is found. No session is required; repeated probes disclose account names but do not by themselves grant account access or modify server data.
Summary
What happened
Username enumeration in UserSpice 4.3.24 allows remote attackers to identify valid accounts through crafted POST requests. The existingUsernameCheck.php endpoint accepts an unauthenticated username, checks whether it exists, and returns the distinguishable text 'taken' when a match is found. No session is required; repeated probes disclose account names but do not by themselves grant account access or modify server data.
The record
- CVE
- CVE-2018-25350
- Published
- May 23, 2026
- Updated
- May 23, 2026
- Vendor
- UserSpice
- Product
- UserSpice
- Classifications
- CWE-204, T1087
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 23, 2026CVE publishedPublication date reported by the CVE source.
- May 23, 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=4.3.24
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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.
Public exploit references
- ExploitDB 44872 UserSpice Username Enumerationfunctional · demonstrated
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Technologies
Your stack
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Your stack
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