CVE-2026-71851: crypto-js: Insufficient Entropy in Cryptographic Secret Generation via Vulnerable CryptoJS Dependency Chain
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
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.
Description quoted from the CVE record (assigned by GitHub_M, published 2026-08-07).
Weakness: CWE-331: Insufficient Entropy; CWE-334: Small Space of Random Values; CWE-338: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
How it can be exploited
Exploitable over the network with high attack complexity needing no privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
CISA assessment (SSVC): CISA assesses that a public proof of concept exists. Automatable: no. Technical impact: total.
Public exploit evidence (Exploit Observer)
Also known as: EUVD-2026-54599, GHSA-rg76-677x-56q9
VEDAS cluster: VEDAS:BELTBAGGERANIUM
Exploit Observer has no public exploit code that names this CVE or one of its aliases.
Vulnerability databases and vendor advisories (8)
Catalogue entries, not exploit evidence.
- Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2026-54599
- Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-rg76-677x-56q9
- Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-71851
- Vulnerability database or vendor advisory: https://osv.dev/vulnerability/CVE-2026-71851
- Vulnerability database or vendor advisory: https://osv.dev/vulnerability/GHSA-rg76-677x-56q9
- Vulnerability database or vendor advisory: https://osv.dev/vulnerability/ROOT-APP-NPM-CVE-2026-71851
- Vulnerability database or vendor advisory: https://osv.dev/vulnerability/UBUNTU-CVE-2026-71851
- Vulnerability database or vendor advisory: https://ubuntu.com/security/CVE-2026-71851
3 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.
VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.
Live scores
- EPSS
- 0.005
low predicted chance of attack - VEDAS
- 0.933
strong exploit evidence - On CISA KEV
- Not listed
- Detection rule
- None yet
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| brix crypto-js | version < 4.0.0 | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
Exploit Observer also maps it to: npm crypto-js.
How to fix it
No fixed version or vendor advisory is listed in the CVE record yet. Watch the vendor’s security page.
How to detect it
There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.
Advisories on this CVE
- “Ill Bloom”: weak CryptoJS RNG made wallet seed phrases guessable (RRWallet, Milo, Bexo, NanChat, Bitcoin Libre) (5 Aug 2026)
References
Other references
- https://github.com/brix/crypto-js/security/advisories/GHSA-rg76-677x-56q9 (x_refsource_CONFIRM)
- https://github.com/brix/crypto-js/commit/b405ff597fb3ac76a7bdfbc72dca10ba1079b1d5 (x_refsource_MISC)
- https://www.coinspect.com/blog/ill-bloom-investigation (x_refsource_MISC)
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.