sm-crypto: Predictable SM2 key generation in Node.js: default RNG uses Math.random + wall clock
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.
Summary
sm-crypto provides JavaScript implementations of the Chinese cryptographic algorithms SM2, SM3, and SM4. Prior to 0.5.0, the default no-argument sm2.generateKeyPairHex() path in Node.js uses the module-wide SecureRandom instance in src/sm2/utils.js, supplied by [email protected], which seeds an ARC4 stream from Math.random() and new Date().getTime() because window.crypto.getRandomValues is unavailable even though globalThis.crypto exists. An attacker who can observe the process's Math.random() outputs and estimate the key-generation time can reconstruct the seed, recover generated SM2 private keys, and predict signing ephemeral scalars used to forge signatures. This issue is fixed in version 0.5.0.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| JuneAndGreen | sm-crypto | before 0.5.0 | 0.5.0 | Patch available | CNA |
| — | sm-crypto (npm) | before 0.5.0 | 0.5.0 | Patch available | GHSA-vh45-f885-3848 |
- sm-crypto VendorJuneAndGreen Affected before 0.5.0 Fixed in 0.5.0 Patch available CNA
- sm-crypto (npm) Vendor— Affected before 0.5.0 Fixed in 0.5.0 Patch available GHSA-vh45-f885-3848
CPE names Threatist (inferred) · 1
Inferred from how NVD named this product before; not given by a source.
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:juneandgreen:sm-crypto:*:*:*:*:*:*:*:* | — | — | JuneAndGreen |
- cpe:2.3:a:juneandgreen:sm-crypto:*:*:*:*:*:*:*:* Versions — — ·JuneAndGreen
Remediation
- Fix · CNA sm-crypto (JuneAndGreen) Fixed in 0.5.0
- Fix · GHSA-vh45-f885-3848 sm-crypto (npm) Fixed in 0.5.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-73567
- 2026-10-03 Alias added: GHSA-vh45-f885-3848
References
More JuneAndGreen vulnerabilities
- TI-2026-19308 sm-crypto Affected by Private Key Recovery in SM2-PKE CVSS 3.1CRITICAL 9.1
- TI-2026-19309 sm-crypto Affected by Signature Malleability in SM2-DSA CVSS 3.1HIGH 7.5
- TI-2026-19307 sm-crypto Affected by Signature Forgery in SM2-DSA CVSS 3.1HIGH 7.5
Sources
- CVE-2026-73567 · CVE Program
- CVE-2026-73567 · NVD
- FIRST EPSS
- GHSA-vh45-f885-3848 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences