CVE-2026-55174

UltrafastSecp256k1: ECDSA adaptor verification accepts non-adaptable pre-signatures due to missing DLEQ binding

Published Sep 30, 2026 CVSS 3.1 · 5.9 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Shrec
Shrec ultrafastsecp256k1
Vendors & Products Shrec
Shrec ultrafastsecp256k1
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title UltrafastSecp256k1: ECDSA adaptor verification accepts non-adaptable pre-signatures due to missing DLEQ binding
Weaknesses CWE-345
CWE-347
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 30, 2026, 7:52 PM
Reserved
Jun 16, 2026, 3:20 PM
Status
Deferred
Published
Sep 30, 2026, 4:17 PM
Modified
Sep 30, 2026, 8:17 PM