CVE-2026-71851: crypto-js is a JavaScript library of crypto standards

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CRITICAL 9.0REMOTE

CVE-2026-71851 is a critical-severity flaw (CVSS 9.0) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

Critical severity
CISA SSVC: public proof of concept
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.0 (Critical)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 55%)
CISA exploited list	No
Weakness	CWE-331, CWE-334, CWE-338
Published	2026-08-07
Last modified	2026-10-24

Publisher (CNA): GitHub, Inc.

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-08-07 19:18 UTCPublished CVE record published
2026-10-24 15:10 UTCUpdated Record last modified

Exact fixes by distribution

npm · crypto-js · FIXED · 4.0.0 · vulnerable: < 4.0.0 · source

npm install crypto-js@">=4.0.0" npm ls crypto-js

Fedora 46 · kwin-zones · FIXED · 1.0.13-1.fc46 · FEDORA-2026-95888f332b · source

sudo dnf upgrade --advisory=FEDORA-2026-95888f332b

Fedora ELN · nginx-mod-brotli · FIXED · 1.0.0~rc-16.eln159 · FEDORA-2026-501a6a8273 · source

sudo dnf upgrade --advisory=FEDORA-2026-501a6a8273

Debian 12 · cryptojs · NO FIX YET

RHEL 10 · dotnet8.0 · NOT AFFECTED

RHEL 10 · dotnet9.0 · NOT AFFECTED

RHEL 8 · dotnet8.0 · NOT AFFECTED

RHEL 8 · dotnet9.0 · NOT AFFECTED

RHEL 9 · dotnet8.0 · NOT AFFECTED

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: brendonlee20042004-sys/weakrng-sweep (0 stars)
Write-up: github.com/brix/crypto-js/security/advisories/GHSA-rg76-677x-56q9

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-71851?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-71851 being exploited?

CVE-2026-71851 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-71851 affect?

CVE-2026-71851 affects affected software. Severity is critical (CVSS 9.0). 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 fro

How urgent is CVE-2026-71851?

Priority 51/100. Critical severity; CISA SSVC: public proof of concept; Remotely exploitable, no login, no user action

References

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