Pseudorandom Number Generation Flaw in crypto-js JavaScript Library
CVE-2026-71851

9CRITICAL

Key Information:

Vendor

Brix

Status
Crypto-js
Vendor
CVE Published:
7 August 2026

What is CVE-2026-71851?

The crypto-js JavaScript library has a vulnerability that originates from its use of a custom pseudorandom number generator for generating randomness in the CryptoJS.lib.WordArray.random() function. This generator, seeded by Math.random(), fails to provide cryptographically secure randomness, making it susceptible to attacks. Since versions prior to 4.0.0, this issue has allowed attackers to enumerate potential outputs, leading to the risk of private key recovery for downstream wallet applications relying on this faulty entropy source for generating BIP39 recovery phrases. Users are strongly advised to upgrade to version 4.0.0 or later to mitigate this risk.

Affected Version(s)

crypto-js < 4.0.0

References

https://github.com/brix/crypto-js/security/advisories/GHS...
x_refsource_CONFIRM
https://github.com/brix/crypto-js/commit/b405ff597fb3ac76...
x_refsource_MISC
https://www.coinspect.com/blog/ill-bloom-investigation
x_refsource_MISC

CVSS V3.1

Score:
9
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.