CVE-2026-73567
sm-crypto: Predictable SM2 key generation in Node.js: default RNG uses Math.random + wall clock
- State
- Published
- Severity
- 9.1 Critical
- Published
- Aug 13, 2026
- Updated
- Aug 14, 2026
- Reserved
- Aug 12, 2026
Description
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 jsbn@1.1.0, 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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 9.1 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N | GitHub_M |
Weaknesses
- CWE-338 Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
Affected Products
| Product | Versions |
|---|---|
sm-cryptoJuneAndGreen |
|
References
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