Quick answers
- Is CVE-2026-55241 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-55241 being exploited in the wild.
- How severe is CVE-2026-55241?
- High severity, with a CVSS score of 7.5, published 21 August 2026.
- Which products and versions are affected?
- Bluewave-Labs Checkmate before 3.9.1.
- Is there a fix for CVE-2026-55241?
- A patch was published on 2026-07-03: v3.9.1 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-55241 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-55241?
- Check whether you run Bluewave-Labs Checkmate 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.
Technical details
The vulnerability is a denial-of-service flaw in the POST /api/v1/auth/register route caused by insufficient file-upload validation. The Multer middleware in server/src/api/middleware/upload.ts lacks file-size, file-count, and MIME-type limits, buffering multipart form data (profileImage uploads) in memory before registration validation or invite-token checks are performed. An unauthenticated attacker can submit concurrent oversized files to exhaust memory and crash or destabilize the backend. The attack requires network access to the public registration endpoint but no authentication or user interaction. The vulnerability was fixed in version 3.9.1 by implementing proper file-upload constraints in the middleware.
Affected products
- Bluewave Labs Checkmate before 3.9.1
Timeline
- 2026-08-21: disclosed
- 2026-07-03: patched: v3.9.1 released