Elysia Cookie Value Prototype Pollution
Impact
Elysia cookie can be overridden by prototype pollution , eg. __proto__
Sending cookie with the follows name can override cookie value:
__proto__=%7B%22injected%22%3A%22polluted%22%7DPatches
Patched by 1.4.27
Workarounds
- Use t.Cookie validation to enforce validation value
- Prevent iterable over cookie if possible
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | elysia | < 1.4.27 | 1.4.27 |
References
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N- Weakness (CWE)
CWE-1321- Platform
- npm
- Package
elysia- Disclosed
- 17.03.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-8hq9-phh3-p2wp - CC BY 4.0
Vulnerability history: elysia
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 5
- First → latest
- 12.2025 09.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 1
- High 3
- Medium 1
Disclosures per year
- 2025: 2
- 2026: 3
-
Elysia Cookie Value Prototype Pollution this entry
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