CVE-2026-32887: Effect is a TypeScript framework that consists of several packages that work together to help build TypeScript

This week

HIGH 7.4REMOTEUPGRADE

CVE-2026-32887 is a high-severity flaw (CVSS 7.4) affecting effect. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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()`

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.4 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 80%)
CISA exploited list	No
Weakness	CWE-362
Published	2026-03-20
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: effectful

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-20 22:16 UTCPublished CVE record published
2026-06-17 10:36 UTCUpdated Record last modified

effectful effect UPGRADE

Affected: < 3.20.0

Fixed in: 3.20.0

Safe to downgrade to: no unaffected older release

1. Check installed version

npm ls effect

2. UPGRADE to 3.20.0

npm install effect@">=3.20.0"

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-32887?

effect: upgrade to 3.20.0. Exact commands for each OS are on this page.

Is CVE-2026-32887 being exploited?

CVE-2026-32887 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-32887 affect?

CVE-2026-32887 affects effect. Severity is high (CVSS 7.4). 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 Ap

How urgent is CVE-2026-32887?

Priority 41/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

Node.js vulnerabilities · Next.js vulnerabilities

References

← Back to latest CVEs