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.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-38f7-945m-qr2g Effect `AsyncLocalStorage` context lost/contaminated inside Effect fibers under concurrent load with RPC
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 20 Mar 2026 21:45:00 +0000

Type Values Removed Values Added
Description 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.
Title Effect Bug: `AsyncLocalStorage` context lost/contaminated inside Effect fibers under concurrent load with RPC
Weaknesses CWE-362
References
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-03-20T21:35:05.853Z

Reserved: 2026-03-16T21:03:44.421Z

Link: CVE-2026-32887

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-03-20T22:16:27.980

Modified: 2026-03-20T22:16:27.980

Link: CVE-2026-32887

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses