CVE-2026-73567 sm-crypto: Predictable SM2 key generation in Node.js: default RNG uses Math.random + wall clock
Attackers can recover SM2 private keys and forge signatures due to predictable random number generation in the sm-crypto library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-73567?
CVE-2026-73567 is a critical vulnerability in JuneAndGreen sm-crypto, published on 13 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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 [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.
Weakness: CWE-338
Which versions are affected by CVE-2026-73567?
2 open source packages ship an affected version, including sm-crypto.
| Package | Affected | Fixed in |
|---|---|---|
sm-crypto npm | All versions | 0.5.0 |
sm-crypto npm | All versions | 0.5.0 |
How do I fix CVE-2026-73567?
Upgrade sm-crypto to 0.5.0 or later.
Is CVE-2026-73567 being exploited?
There is no known exploitation of CVE-2026-73567 in the wild and no public exploit code.
Sources
Also known as GHSA-vh45-f885-3848.