CVE-2026-115779

Effect is a TypeScript framework that consists of several packages that work together to help build TypeScript applications. From @effect/platform 0.1.0 until 0.97.1 and effect 4.0.0-beta.0 until 4.0.0-beta.103, the name, domain, and path fields passed to makeCookie() allow semicolon delimiters that serializeCookie() writes verbatim into Set-Cookie headers. A caller that supplies attacker-controlled values can append cookie attributes, including a broader Domain or, when the caller has not set those options itself, SameSite=None or Max-Age. Encoded cookie values and CR or LF characters remain unaffected. This can widen a cookie's scope or add otherwise-unset cookie attributes. This issue is fixed in @effect/platform 0.97.1 and effect 4.0.0-beta.103.