{“lastseen”:””,”description”:”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.”,”published”:”2025-12-09T19:43:10.252Z”,”modified”:”2025-12-09T19:43:10.252Z”,”type”:”cve”,”title”:”Elysia vulnerable to prototype pollution with multiple standalone schema validation”,”source”:”GitHub_M”,”references”:”https:\/\/github.com\/elysiajs\/elysia\/security\/advisories\/GHSA-hxj9-33pp-j2cc\\nhttps:\/\/github.com\/elysiajs\/elysia\/security\/advisories\/GHSA-8vch-m3f4-q8jf\\nhttps:\/\/github.com\/elysiajs\/elysia\/pull\/1564\\nhttps:\/\/github.com\/elysiajs\/elysia\/commit\/26935bf76ebc43b4a43d48b173fc853de43bb51e\\nhttps:\/\/github.com\/elysiajs\/elysia\/commit\/3af978663e437dccc6c1a2a3aff4b74e1574849e”,”id”:”CVE-2025-66456″,”bulletinFamily”:””,”cwe”:[“CWE-1321″],”cvelist”:null,”sourceData”:”elysiajs elysia \\u003e= 1.4.0, \\u003c 1.4.17″,”sourceHref”:””,”cvss”:{“score”:9.1,”severity”:”CRITICAL”,”vector”:”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”,”version”:”4.0″},”cvss2″:{},”cvss3″:{“version”:””,”vectorString”:””,”baseScore”:0,”baseSeverity”:””,”attackVector”:””,”attackComplexity”:””,”privilegesRequired”:””,”userInteraction”:””,”scope”:””,”confidentialityImpact”:””,”integrityImpact”:””,”availabilityImpact”:””,”cvssV3″:{“version”:””,”vectorString”:””,”baseScore”:0,”baseSeverity”:””,”attackVector”:””,”attackComplexity”:””,”privilegesRequired”:””,”userInteraction”:””,”scope”:””,”confidentialityImpact”:””,”integrityImpact”:””,”availabilityImpact”:””}},”href”:””,”category_name”:”CVE”,”post_link”:””,”product”:”elysia”,”version”:”\\u003e= 1.4.0, \\u003c 1.4.17″,”vendor”:”elysiajs”,”ai_description”:”Prototype pollution vulnerability in `mergeDeep` allowing for full RCE by an attacker when combined with GHSA-8vch-m3f4-q8jf”,”ai_severity”:”Critical”,”ai_vendor”:”elysiajs”,”ai_product”:”elysia”,”ai_version”:”1.4.0-1.4.16″,”ai_score”:9.1}<\/p>\n","protected":false},"excerpt":{"rendered":"
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