CVE-2025-66457
8.8 · HIGHOverview
CVE-2025-66457 is a high-severity vulnerability affecting elysiajs elysia. It was published on December 9, 2025 and has a CVSS 3.1 base score of 8.8 (HIGH).
This vulnerability has a CVSS 3.1 base score of 8.8, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical Description
Elysia is a Typescript framework for request validation, type inference, OpenAPI documentation and client-server communication. Versions 1.4.17 and below are subject to arbitrary code execution from cookie config. When dynamic cookies are enabled (e.g. there an existing cookie schema), the cookie config is injected into the compiled route without first being sanitised. Availability of this exploit is generally low, but when combined with GHSA-hxj9-33pp-j2cc, it allows for a full RCE chain. An attack requires write access to either the Elysia app's source code (in which case the vulnerability is meaningless) or write access to the cookie config (perhaps where it is assumed to be provisioned by the environment). This issue is fixed in version 1.4.18.
Remediation
Check the references section for vendor advisories and patches from elysiajs. Update elysia to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| elysiajs | elysia | >= 0, < 1.4.18 | Affected |
References
Frequently Asked Questions
What is CVE-2025-66457?
CVE-2025-66457 is a high-severity vulnerability affecting elysiajs elysia. It was published on December 9, 2025 and has a CVSS 3.1 base score of 8.8 (HIGH).
How severe is CVE-2025-66457?
This vulnerability has a CVSS 3.1 base score of 8.8, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2025-66457?
Check the references section for vendor advisories and patches from elysiajs. Update elysia to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2025-66457?
CyberStrike's AI-powered security agents can automatically detect CVE-2025-66457 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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