CVE-2026-23965
A signature forgery vulnerability exists in the SM2 signature verification logic of sm-crypto prior to version 0.4.0.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.21%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
sm-crypto provides JavaScript implementations of the Chinese cryptographic algorithms SM2, SM3, and SM4. A signature forgery vulnerability exists in the SM2 signature verification logic of sm-crypto prior to version 0.4.0. Under default configurations, an attacker can forge valid signatures for arbitrary public keys. If the message space contains sufficient redundancy, the attacker can fix the prefix of the message associated with the forged signature to satisfy specific formatting requirements. Version 0.4.0 patches the issue.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 0.21% probability · 11th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-347
- Affected
- juneandgreen/sm-crypto
- Source
- security-advisories@github.com
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.