| Package | Affected versions | Patched versions |
|---|---|---|
| crypto-js | < 4.0.0 | 4.0.0 |
CryptoJS.lib.WordArray.random() in affected versions is not a cryptographically secure random number generator. Nominal requests for 128 or 256 bits of entropy produce effective search spaces of approximately 2^39 and 2^47 possibilities — small enough to enumerate on commodity hardware.
Coinspect's Ill Bloom investigation confirmed that downstream wallet applications used this function as the entropy source for BIP39 recovery phrases.
An application is affected only if it uses the vulnerable function to generate security-sensitive values.
Merely depending on crypto-js < 4.0.0 is not sufficient to be exploitable.
The affected implementation used a custom variation of George Marsaglia's Multiply-With-Carry PRNG, seeded from Math.random(). It was introduced in 3.1.2-4 (June 2014, commit brix/crypto-js@ff1f003) in response to issue #7, and was present in every 3.x release except 3.2.0 and 3.2.1. That change was reverted in 3.3.0 because it was considered a breaking change, so projects tracking the 3.x line could resolve to newer versions that still contained the weak generator.
4.0.0 replaced the generator with the platform's native cryptographic API.
Applying PBKDF2, another KDF, or a cryptographic hash after the vulnerable generator does not restore missing entropy.
Coinspect reproduced the attack end to end:
WordArray.random() behavior.An attacker can enumerate the reduced output space and recover security-sensitive values generated through the affected function.
Coinspect documented coordinated drain waves affecting addresses derived from vulnerable recovery phrases. As of July 13, 2026, the measured lower bound of stolen assets across the two events was approximately $5M.
The consequences are persistent:
For projects:
crypto-js to version 4.0.0 or later. Where possible, replace CryptoJS randomness with the native Web Crypto API or Node.js crypto module.crypto-js matching < 4.0.0.CryptoJS.lib.WordArray.random() was used to generate any security-sensitive values.For wallet users: create a new wallet with a newly generated recovery phrase from a trustworthy source and migrate assets to addresses derived from it. Do not import the existing recovery phrase into the new wallet.
Coinspect provides a public checker for addresses identified in the known Ill Bloom exposed-address datasets:
Only public blockchain addresses should be entered. Users must never enter a recovery phrase, seed phrase, mnemonic, private key, password, or wallet backup file.
A match indicates that funds controlled by the same recovery phrase may be at immediate risk. A negative result only means that the submitted address was not found in the currently published datasets.
randomBytes is not random enough:3.3.0 and 4.0.0:ferrumnet/bip39 fork:Running one of these products? Scan your site to see whether it exposes a vulnerable version.
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