dai-shi use-reducer-async Postinstall Script src/install.js code injection

Summaryinfo

A vulnerability marked as critical has been reported in dai-shi use-reducer-async. Affected by this issue is some unknown functionality of the file src/install.js of the component Postinstall Script. The manipulation leads to code injection. This vulnerability is traded as CVE-2026-48159. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in dai-shi use-reducer-async (the affected version is unknown). This issue affects an unknown code of the file src/install.js of the component Postinstall Script. The manipulation with an unknown input leads to a code injection vulnerability. Using CWE to declare the problem leads to CWE-94. The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-48159 since 05/21/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1059 according to MITRE ATT&CK.

Applying the patch df07d5711458d8b46e11dd7afaaa21e88cafabfb is able to eliminate this problem.

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Productinfo

Vendor

• dai-shi

Name

• use-reducer-async

Website

• Product: https://github.com/dai-shi/use-reducer-async/

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