CVE-2026-55241

Checkmate is an open-source, self-hosted tool designed to track and monitor server hardware, uptime, response times, and incidents in real-time with beautiful visualizations. Prior to 3.9.1, the public POST /api/v1/auth/register route in server/src/api/routes/authRoutes.ts passes multipart profileImage uploads through in-memory Multer parsing before registration validation, without file-size, file-count, or MIME-type limits in server/src/api/middleware/upload.ts. An unauthenticated attacker can submit concurrent oversized files that are buffered before invalid registration or invite-token checks reject the request, exhausting memory and crashing or destabilizing the backend. This issue is fixed in version 3.9.1.

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.6% chance of exploitation in the next 30 days; higher than 49% of CVEs (scores of 2026-10-25)

CWEs

CWE-400, CWE-770

Published

2026-08-21

Modified

2026-10-14

Record from

the NVD, synced 2026-10-19

References

• https://github.com/bluewave-labs/Checkmate/commit/091c36cbf338b673110b0806d76df26d52516468
• https://github.com/bluewave-labs/Checkmate/releases/tag/v3.9.1
• https://github.com/bluewave-labs/Checkmate/security/advisories/GHSA-9xvg-x28f-m78m
• https://github.com/bluewave-labs/Checkmate/security/advisories/GHSA-9xvg-x28f-m78m

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