# CVE-2026-122138: BlueprintUE Self-Hosted Edition 4.2.0 before 4.3.4 Login Rate Limit Bypass

Status: published. Published: 2026-11-04. Updated: 2026-11-04.

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.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/blueprintue/blueprintue-self-hosted-edition/commit/bd4af38d2f7d499be23fc4106f93980a1348ddd7
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/blueprintue/blueprintue-self-hosted-edition/pull/267

## Affected products and versions

- blueprintue / blueprintue-self-hosted-edition (blueprintue/blueprintue-self-hosted-edition): ≥ 4.2.0; < 4.3.4 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 6.3 (medium); CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 5.3 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-307

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/blueprintue/blueprintue-self-hosted-edition/security/advisories/GHSA-773r-585g-6vc3 (CNA: VulnCheck; vendor-advisory)

- https://github.com/blueprintue/blueprintue-self-hosted-edition/commit/bd4af38d2f7d499be23fc4106f93980a1348ddd7 (CNA: VulnCheck; patch)

- https://github.com/blueprintue/blueprintue-self-hosted-edition/pull/267 (CNA: VulnCheck; patch, issue-tracking)

- https://github.com/blueprintue/blueprintue-self-hosted-edition/releases/tag/v4.3.4 (CNA: VulnCheck; release-notes)

- https://github.com/blueprintue/blueprintue-self-hosted-edition/blob/v4.3.3/app/middlewares/LoginMiddleware.php#L119-L158 (CNA: VulnCheck; technical-description)

- https://www.vulncheck.com/advisories/blueprintue-self-hosted-edition-4.2.0-before-4.3.4-login-rate-limit-bypass (CNA: VulnCheck; third-party-advisory)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-122138; retrieved 2026-11-04; source updated 2026-11-04

Revision: dd6593c4b6fe7b34fd63b5bfcf15261e29e0587c0c800bba5e0b10d8d2916542

Canonical: https://y2.dev/cve/CVE-2026-122138

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.