CVE-2025-66457

HIGH EPSS 47.7%
Published Dec 9, 20256mo ago · Modified Jun 17, 20262w ago
7.5 CVSS 4.0
High
Find Similar
Published Dec 9, 2025 6mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
7.5
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required High
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
47.7% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-94 Improper Control of Generation of Code (Code Injection) Injection

Affected Products 1

VendorProductVersionRange
elysiajselysia* <1.4.18

References 6

  • github.com https://github.com/elysiajs/elysia/commit/26935bf76ebc43b4a43d48b173fc853de43bb51e
    Patch
  • github.com https://github.com/elysiajs/elysia/commit/3af978663e437dccc6c1a2a3aff4b74e1574849e
    Patch
  • github.com https://github.com/elysiajs/elysia/pull/1564
    Issue TrackingPatch
  • github.com https://github.com/elysiajs/elysia/security/advisories/GHSA-8vch-m3f4-q8jf
    ExploitPatchVendor Advisory
  • github.com https://github.com/elysiajs/elysia/security/advisories/GHSA-hxj9-33pp-j2cc
    Not Applicable
  • github.com https://github.com/sportshead/elysia-poc
    ExploitThird Party Advisory

Remediation

  • github.com https://github.com/elysiajs/elysia/commit/26935bf76ebc43b4a43d48b173fc853de43bb51e
    Patch
  • github.com https://github.com/elysiajs/elysia/commit/3af978663e437dccc6c1a2a3aff4b74e1574849e
    Patch
  • github.com https://github.com/elysiajs/elysia/pull/1564
    Issue TrackingPatch
  • github.com https://github.com/elysiajs/elysia/security/advisories/GHSA-8vch-m3f4-q8jf
    ExploitPatchVendor Advisory