CVE-2026-55241
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.44%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.44% probability · 37th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-400, CWE-770
- Source
- security-advisories@github.com
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.