Description
UltrafastSecp256k1 is a high-performance, multi-backend secp256k1 engine with reproducible audit evidence, compatibility shims, and profile-based review scopes. Prior to version 4.2.0, UltrafastSecp256k1's ECDSA adaptor pre-signature verification accepts forged adaptor pre-signatures whose "r" value is not cryptographically bound to the adaptor point "T". This issue has been patched in version 4.2.0.
References5
- github.com/shrec/UltrafastSecp256k1/commit/5478ef566c6af91b48a4…
- github.com/shrec/UltrafastSecp256k1/releases/tag/v4.2.0
- github.com/shrec/UltrafastSecp256k1/releases/tag/v4.2.1
- github.com/shrec/UltrafastSecp256k1/security/advisories/GHSA-c7…
- github.com/shrec/UltrafastSecp256k1/security/advisories/GHSA-c7…
Metrics
- CVSS 3.1
-
5.9
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N - EPSS — exploit probability
- 0% percentile: 4 · as of 10 November 2026
- CWE
- CWE-345CWE-347
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.