---
id: CVE-2026-48159
title: use-reducer-async is a React useReducer with async actions
summary: >-
  use-reducer-async is a React useReducer with async actions. Between 2026-05-18
  16:29:52 and 2026-05-19 15:26:07, the default branch contained malicious
  commits da72edbde5705efcec6c62e0a3dcb73687b78dc8 through
  df07d5711458d8b46e11dd7afaaa…
severity: none
cwe:
  - CWE-506
published: '2026-08-10'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T20:54:37.790'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-48159'
references:
  - url: >-
      https://github.com/dai-shi/use-reducer-async/security/advisories/GHSA-2786-p4vj-vx8x
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00488
epssPercentile: 0.41002
ingestedAt: '2026-09-08T21:11:12.273Z'
---

## Overview

use-reducer-async is a React useReducer with async actions. Between 2026-05-18 16:29:52 and 2026-05-19 15:26:07, the default branch contained malicious commits da72edbde5705efcec6c62e0a3dcb73687b78dc8 through df07d5711458d8b46e11dd7afaaa21e88cafabfb that executed remote attacker-controlled code on developer machines during `npm install`. The commits were removed by force-push, but local clones, forks, and direct-SHA URLs may still contain them, and `npm install` against an affected checkout will still execute the code today. The package was not published to npm. `src/install.js` was added and wired into the `postinstall` script. It fetched a JavaScript payload from an attacker-controlled HTTPS endpoint (configurable via an environment variable), disabled TLS verification, and evaluated the response as code with `require` available. Execution was deliberately skipped on CI and cloud/serverless environments, targeting developer workstations. The second-stage payload was attacker-hosted and cannot be reconstructed. Assume full compromise of anything reachable from a Node process with the user's permissions. Those who ran `npm install` against an affected checkout on a developer machine on or after 2026-05-18 16:29:52 should treat the machine as compromised, rotate every credential the machine could reach, audit account activity since 2026-05-18 16:29:52, and clean local clones.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.