CVE-2026-55174
UltrafastSecp256k1: ECDSA adaptor verification accepts non-adaptable pre-signatures due to missing DLEQ binding
- State
- Published
- Severity
- 5.9 Medium
- Published
- Sep 30, 2026
- Updated
- Sep 30, 2026
- Reserved
- Jun 16, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 5.9 Medium | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N | GitHub_M |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
UltrafastSecp256k1shrec |
|
References
- https://github.com/shrec/UltrafastSecp256k1/security/advisories/GHSA-c7q2-gv3g-rgxm
- https://github.com/shrec/UltrafastSecp256k1/commit/5478ef566c6af91b48a45c0c61f161f5b1071981
- https://github.com/shrec/UltrafastSecp256k1/releases/tag/v4.2.0
- https://github.com/shrec/UltrafastSecp256k1/releases/tag/v4.2.1
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