Account compromise via unrestricted login attempts
Published Apr 21, 2026 · Updated Apr 21, 2026
Improper restriction of login attempts in blueprintUE Self-Hosted Edition before 4.2.0 allows remote attackers to guess account passwords. The LoginMiddleware.php doProcessLogin() handler accepts repeated password submissions without an IP or account counter, lockout, delay, or CAPTCHA. The login route requires no authentication; a valid CSRF token and known username enable dictionary attacks or credential stuffing, and a successful guess grants access to the targeted account.
Summary
What happened
Improper restriction of login attempts in blueprintUE Self-Hosted Edition before 4.2.0 allows remote attackers to guess account passwords. The LoginMiddleware.php doProcessLogin() handler accepts repeated password submissions without an IP or account counter, lockout, delay, or CAPTCHA. The login route requires no authentication; a valid CSRF token and known username enable dictionary attacks or credential stuffing, and a successful guess grants access to the targeted account.
The record
- CVE
- CVE-2026-40586
- Published
- Apr 21, 2026
- Updated
- Apr 21, 2026
- Vendor
- blueprintUE
- Product
- blueprintUE Self-Hosted Edition
- Classifications
- CWE-307, T1110.001, T1110.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 21, 2026CVE publishedPublication date reported by the CVE source.
- Apr 21, 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=< 4.2.0
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.
Weakness, pattern, technique
Public exploit references
- GHSA proof-of-concept login requestproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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