CVE-2019-25005: CHACHA20 Project CHACHA20

High severity, CVSS 7.5. EPSS: 1.3% chance of exploitation in the next 30 days.

An issue was discovered in the chacha20 crate before 0.2.3 for Rust. A ChaCha20 counter overflow makes it easier for attackers to determine plaintext.

Affected products

• CHACHA20 Project CHACHA20: before 0.2.3 (fixed in 0.2.3)

Published 2020-12-31. Last modified 2026-06-17.