CVE-2021-43572: Starkbank Ecdsa-Python

Critical severity, CVSS 9.8. EPSS: 1.2% chance of exploitation in the next 30 days.

The verify function in the Stark Bank Python ECDSA library (aka starkbank-escada or ecdsa-python) before 2.0.1 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages.

Affected products

• Starkbank Ecdsa-Python: before 2.0.1 (fixed in 2.0.1)

Published 2021-11-09. Last modified 2026-06-17.