CVE-2026-55174CWE-345CWE-347

CVE-2026-55174

Medium · published September 30, 2026

CVSS v3.1
5.9
EPSS
0%
Percentile
3.9
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
5.9 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00150 · 3.9th percentile
Weaknesses
CWE-345 · Insufficient Verification of Data Authenticity; CWE-347 · Improper Verification of Cryptographic Signature
Published
2026-09-30T20:17Z
References (5)
https://github.com/shrec/UltrafastSecp256k1/releases/tag/v4.2.1 · [email protected]https://github.com/shrec/UltrafastSecp256k1/security/advisories/GHSA-c7q2-gv3g-rgxm · [email protected]https://github.com/shrec/UltrafastSecp256k1/security/advisories/GHSA-c7q2-gv3g-rgxm · 134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/shrec/UltrafastSecp256k1/commit/5478ef566c6af91b48a45c0c61f161f5b1071981 · [email protected]https://github.com/shrec/UltrafastSecp256k1/releases/tag/v4.2.0 · [email protected]
EPSS history
Timeline
  • 02 OCT 03:44Z
    EPSS moved — → 0%
    epss
  • 30 SEP 15:49Z
    UltrafastSecp256k1: ECDSA adaptor verification accepts non-adaptable pre-signatures due to missing DLEQ binding
    cvelistv5