vulnerability / NVI-00016353 / Revision 2
crypto-js: Insufficient Entropy in Cryptographic Secret Generation via Vulnerable CryptoJS Dependency Chain
GitHub lists this reviewed advisory for crypto-js. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
9 critical
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
9 CRITICAL (3.1)
security-advisories@github.com severity; no combined Null risk score.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
crypto-js
source listed< 4.0.0
### Summary `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. ### Details 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.
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. NIST National Vulnerability Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
- NVD lastModified does not establish freshness of every associated CPE record.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-rg76-677x-56q9 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- CVE-2026-71851 ↗
NIST National Vulnerability Database · official catalog
Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 2 ·
Source facts changed; compare the preserved prior revision.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.