All vulnerabilities
CVE-2026-55174GHSA-c7q2-gv3g-rgxm

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

shrec UltrafastSecp256k1
Open in ThreatlineRecord JSON
CVSS
5.9Medium
ExploitationPublic exploit codeCISA's assessment says proof of concept code is public, assessed 30 Sep 2026. Not in the KEV catalogCISA via CVE List
Exploit odds (EPSS)0.15%Chance of exploitation activity in the next 30 days, higher than 3% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published30 Sep 2026Updated 30 Sep 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

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.

Text from CVE List

Affected versions 1

  • UltrafastSecp256k1affected: < 4.2.0CVE List

References 4