brix crypto-js up to 3.x Generator CryptoJS.lib.WordArray.random random values

Summaryinfo

A vulnerability categorized as problematic has been discovered in brix crypto-js up to 3.x. Affected by this issue is the function CryptoJS.lib.WordArray.random of the component Generator. Such manipulation leads to random values. This vulnerability is referenced as CVE-2026-71851. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability was found in brix crypto-js up to 3.x. It has been rated as problematic. Affected by this issue is the function CryptoJS.lib.WordArray.random of the component Generator. The manipulation with an unknown input leads to a random values vulnerability. Using CWE to declare the problem leads to CWE-330. The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers. Impacted is confidentiality. CVE summarizes:

crypto-js is a JavaScript library of crypto standards. Versions of crypto-js prior to 4.0.0 generate randomness in CryptoJS.lib.WordArray.random() using a custom variation of the Multiply-With-Carry pseudorandom number generator, seeded from Math.random(), instead of a cryptographically secure source. This generator was introduced in version 3.1.2-4 and remained present in nearly every 3.x release. Nominal requests for 128 or 256 bits of entropy through this function produce effective search spaces of approximately 2 to the 39th and 2 to the 47th possibilities, small enough to enumerate on commodity hardware. Downstream wallet applications that used CryptoJS.lib.WordArray.random() as the entropy source for BIP39 recovery phrases are affected, and an attacker who enumerates the reduced output space can recover the resulting private keys and control the associated funds. This issue is fixed in version 4.0.0.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-71851 since 08/07/2026. The exploitation is known to be difficult. The attack may be launched remotely. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1600.001.

Upgrading to version 4.0.0 eliminates this vulnerability.

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Productinfo

Vendor

• brix

Name

• crypto-js

Version

• 3.x

Website

• Product: https://github.com/brix/crypto-js/

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