CVE-2026-56669 elysiajs CVE debrief

Who should care

Users of the Elysia framework, particularly those who utilize multipart/form-data endpoints, should be aware of this vulnerability and take steps to update to version 1.4.29 or apply compensating controls to mitigate the risk of CPU exhaustion. Operators, platform administrators, and security teams should review their environments for affected deployments.

Technical summary

The Elysia framework, used for request validation, type inference, OpenAPI documentation, and client-server communication, is vulnerable to CPU exhaustion due to improper handling of multipart/form-data endpoints. Specifically, the use of getAll in form data normalization allows the amount of work to grow quadratically with the number of unique key-value pairs, potentially leading to CPU exhaustion. This issue has been addressed in version 1.4.29. Users should review their deployments and update to the latest version.

Defensive priority

High

Recommended defensive actions

• Update to Elysia framework version 1.4.29 or later
• Implement compensating controls to mitigate the risk of CPU exhaustion
• Monitor for suspicious activity on multipart/form-data endpoints
• Perform inventory checks to identify affected systems
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed

Evidence notes

The CVE record was published on 2026-07-08T21:16:50.690Z and last modified on 2026-07-10T16:16:34.777Z. The NVD entry is currently receiving updates. Further verification is needed to confirm affected scope and vendor guidance.

Official resources