CVE-2026-32887
CVE-2026-32887 is a high-severity vulnerability in Effectful Effect with a CVSS 3.x base score of 7.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-362.
Key facts
- Severity: High (CVSS 3.x base score 7.4)
- EPSS exploit prediction: 0% (19th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-13818
- Weakness: CWE-362
- Affected product: Effectful Effect
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-32887?
- 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.
- How severe is CVE-2026-32887?
- CVE-2026-32887 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
- Is CVE-2026-32887 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-32887?
- CVE-2026-32887 affects Effectful Effect. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2026-32887?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-32887 have an EU (EUVD) identifier?
- Yes. CVE-2026-32887 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-13818.
- When was CVE-2026-32887 published?
- CVE-2026-32887 was published on 2026-03-20 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:a:effectful:effect:*:*:*:*:*:node.js:*:*
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