CVE-2026-32887
March 20, 2026
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.
Affected Packages
effect (NPM):
Affected version(s) >=0.0.0-snapshot-a5ad9d748a9f2655de9c9dbe76597867a218e45b <3.20.0Fix Suggestion:
Update to version 3.20.0effect (NPM):
Affected version(s) >=0.0.0-snapshot-a5ad9d748a9f2655de9c9dbe76597867a218e45b <3.20.0Fix Suggestion:
Update to version 3.20.0effect (NPM):
Affected version(s) >=0.0.0-snapshot-a5ad9d748a9f2655de9c9dbe76597867a218e45b <3.20.0Fix Suggestion:
Update to version 3.20.0effect (NPM):
Affected version(s) >=0.0.0-snapshot-a5ad9d748a9f2655de9c9dbe76597867a218e45b <3.20.0Fix Suggestion:
Update to version 3.20.0effect (NPM):
Affected version(s) >=0.0.0-snapshot-a5ad9d748a9f2655de9c9dbe76597867a218e45b <3.20.0Fix Suggestion:
Update to version 3.20.0Related Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
9.1
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.4
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
EPSS
Base Score:
0.01
