CVE-2025-66456

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Source
https://cve.org/CVERecord?id=CVE-2025-66456
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-66456.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2025-66456
Aliases
Related
Published
2025-12-09T19:43:10.252Z
Modified
2026-04-10T05:35:15.919806Z
Severity
  • 9.1 (Critical) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N CVSS Calculator
Summary
Elysia vulnerable to prototype pollution with multiple standalone schema validation
Details

Elysia is a Typescript framework for request validation, type inference, OpenAPI documentation and client-server communication. Versions 1.4.0 through 1.4.16 contain a prototype pollution vulnerability in mergeDeep after merging results of two standard schema validations with the same key. Due to the ordering of merging, there must be an any type that is set as a standalone guard, to allow for the __proto__ prop to be merged. When combined with GHSA-8vch-m3f4-q8jf this allows for a full RCE by an attacker. This issue is fixed in version 1.4.17. To workaround, remove the __proto__ key from body.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66456.json",
    "cwe_ids": [
        "CWE-1321"
    ]
}
References

Affected packages

Git / github.com/elysiajs/elysia

Affected ranges

Type
GIT
Repo
https://github.com/elysiajs/elysia
Events
Introduced
9593648d4289e262035821179e73f16a3271dee9
Fixed
428b9765af69739897b86c294563af8809dd40c3

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-66456.json"