CVE-2021-38196: Better-Macro Project Better-Macro

Critical severity, CVSS 9.8. EPSS: 2.6% chance of exploitation in the next 30 days.

An issue was discovered in the better-macro crate through 2021-07-22 for Rust. It intentionally demonstrates that remote attackers can execute arbitrary code via proc-macros, and otherwise has no legitimate purpose.

Affected products

• Better-Macro Project Better-Macro: up to and including 2021-07-22

Published 2021-08-08. Last modified 2026-06-17.