CVE-2026-32887 — Effect Bug: `AsyncLocalStorage` context lost/contaminated inside Effect fibers under concurrent load with RPC
Effect is a TypeScript framework that consists of several packages that work together to help build TypeScript applications. Prior to version 3.20.0, when using `RpcServer.toWeb…
Published: 2026-03-20 · CVSS: 7.4 · CVSS 3.1
Effect is a TypeScript framework that consists of several packages that work together to help build TypeScript applications. Prior to version 3.20.0, when using `RpcServer.toWebHandler` (or `HttpApp.toWebHandlerRuntime`) inside a Next.js App Router route handler, any Node.js `AsyncLocalStorage`-dependent API called from within an Effect fiber can read another concurrent request's context — or no context at all. Under production traffic, `auth()` from `@clerk/nextjs/server` returns a different user's session. Version 3.20.0 contains a fix for the issue.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7