# CVE-2026-122138: BlueprintUE Self-Hosted Edition login rate limit bypass

Source: https://junglewise.ai/threats/cve-2026-122138-blueprintue-self-hosted-edition-4-2-0-before-4-3-4-contains-a  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-04. Updated: 2026-11-04  
License: CC BY 4.0 with a link back

CVE-2026-122138 · Severity: medium · CVSS 5.3 · Published 2026-11-04

BlueprintUE Self-Hosted Edition is a self-hosted web application platform. An unauthenticated attacker can bypass the login rate limit protection by varying the case of the username during login attempts, allowing them to brute-force passwords without being locked out. This enables account takeover if weak passwords are used.

Technologies: [BlueprintUE Self-Hosted Edition](https://junglewise.ai/threats/technologies/self-hosted-edition). Vendors: [BlueprintUE](https://junglewise.ai/threats/vendors/blueprintue).

## Quick answers

**Is CVE-2026-122138 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-122138 being exploited in the wild.

**How severe is CVE-2026-122138?** Medium severity, with a CVSS score of 5.3, published 4 November 2026.

**Which products and versions are affected?** BlueprintUE Self-Hosted Edition 4.2.0 before 4.3.4.

**Is there a fix for CVE-2026-122138?** Yes: fixed in 4.3.4. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-122138 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-122138?** Check whether you run BlueprintUE Self-Hosted Edition at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 4.3.4

## Technical details

The LoginMiddleware.php component keys failed-login rate limit counters on the case-sensitive username, while the database uses case-insensitive lookups. An attacker can vary username casing (e.g., "admin", "Admin", "ADMIN") to evade the per-account lockout mechanism. The vulnerability requires network access and no authentication; the fix applies mb_strtolower() to normalize usernames when checking rate limits.

## Affected products

- BlueprintUE Self-Hosted Edition 4.2.0 before 4.3.4

## Timeline

- 2026-11-04: disclosed

## References

- [https://github.com/blueprintue/blueprintue-self-hosted-edition/blob/v4.3.3/app/middlewares/LoginMiddleware.php](https://github.com/blueprintue/blueprintue-self-hosted-edition/blob/v4.3.3/app/middlewares/LoginMiddleware.php)
- [https://github.com/blueprintue/blueprintue-self-hosted-edition/commit/bd4af38d2f7d499be23fc4106f93980a1348ddd7](https://github.com/blueprintue/blueprintue-self-hosted-edition/commit/bd4af38d2f7d499be23fc4106f93980a1348ddd7)

## Related threats

- [blueprintUE Self-Hosted Edition insecure database default configuration](https://junglewise.ai/threats/cve-2026-126812-blueprintue-self-hosted-edition-before-4-3-7-contains-an)
- [BlueprintUE Self-Hosted Edition resource exhaustion in blueprint creation](https://junglewise.ai/threats/cve-2026-126659-blueprintue-self-hosted-edition-1-0-0-before-4-3-5-contains-a)
- [blueprintUE Self-Hosted Edition account enumeration in password reset](https://junglewise.ai/threats/cve-2026-122139-blueprintue-self-hosted-edition-before-4-3-3-contains-an-account)