---
cve: "CVE-2026-31865"
severity: "MEDIUM"
cvss: 6.5
epss: "23%"
vendor: "elysiajs"
kev: false
exploited: false
published: "2026-03-18 04:17:19"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-06T14:39:26+02:00"
---

# CVE-2026-31865

> 6.5 MEDIUM · 🧪 PoC

## Beschreibung

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-Vektor

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

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Gering | warn |
| I Integrität | Gering | warn |
| A Verfügbarkeit | Keine | good |

## Patch verfügbar (OSV)

- cc9159b5c60a8eb16bbac4525005e2b5880d3624 (Commit)
- e9d6b1743fa7368ef942dce181f6a089757f6aab (Commit)

## Referenzen

- <https://github.com/elysiajs/elysia/security/advisories/GHSA-8hq9-phh3-p2wp>
- <https://github.com/elysiajs/elysia/commit/e9d6b1743fa7368ef942dce181f6a089757f6aab>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-31865) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_