CVE-2026-55174
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.
- Published Sep 30, 2026
- CVSS 5.9 medium
- 0.1% chance of exploitation in the next 30 days (EPSS)
- A fix is available