Vulnerability in Blueprintue Blueprintue-Self-Hosted-Edition
CVE-2026-122138
BlueprintUE Self-Hosted Edition 4.2.0 before 4.3.4 contains a login rate limit bypass vulnerability in LoginMiddleware.php that keys failed-login counters on case-sensitive usernames. Unauthenticated attackers can vary username casing against case-insensitive MySQL lookups to get extra attempts and brute-force passwords past the per-account lockout.
Published .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (26.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 26.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
The 30-day trend appears once there are two daily scores.
Affected products
Weakness classification (CWE)
References
- github.com/blueprintue/blueprintue-self-hosted-edition/blob/v4.3.3/app/middlewa… (technical-description)
- github.com/blueprintue/blueprintue-self-hosted-edition/commit/bd4af38d2f7d499be… (patch)
- github.com/blueprintue/blueprintue-self-hosted-edition/pull/267 (issue-tracking, patch)
- github.com/blueprintue/blueprintue-self-hosted-edition/releases/tag/v4.3.4 (release-notes)
- github.com/blueprintue/blueprintue-self-hosted-edition/security/advisories/GHSA… (vendor-advisory)
- www.vulncheck.com/advisories/blueprintue-self-hosted-edition-4.2.0-before-4.3.4… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-122138?
- CVE-2026-122138 is a medium-severity vulnerability in Blueprintue Blueprintue-Self-Hosted-Edition, classified under Improper Restriction of Excessive Authentication Attempts. CVSS score: 5.3/10. Published 2026-11-04.
- How severe is CVE-2026-122138?
- Medium severity. CVSS v3 base score is 5.3 out of 10.