Vulnerability Description
Elysia is a Typescript framework for request validation, type inference, OpenAPI documentation, and client-server communication. Prior to version 1.4.27, an Elysia cookie can be overridden by prototype pollution , eg. `__proto__`. This issue is patched in 1.4.27. As a workaround, use t.Cookie validation to enforce validation value and/or prevent iterable over cookie if possible.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Elysiajs | Elysia | < 1.4.27 |
Related Weaknesses (CWE)
References
- https://github.com/elysiajs/elysia/commit/e9d6b1743fa7368ef942dce181f6a089757f6aPatch
- https://github.com/elysiajs/elysia/security/advisories/GHSA-8hq9-phh3-p2wpMitigationPatchVendor Advisory
FAQ
What is CVE-2026-31865?
CVE-2026-31865 is a vulnerability with a CVSS score of 6.5 (MEDIUM). Elysia is a Typescript framework for request validation, type inference, OpenAPI documentation, and client-server communication. Prior to version 1.4.27, an Elysia cookie can be overridden by prototyp...
How severe is CVE-2026-31865?
CVE-2026-31865 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-31865?
Check the references section above for vendor advisories and patch information. Affected products include: Elysiajs Elysia.