CVE-2021-24045: Facebook Hermes

Critical severity, CVSS 9.8. EPSS: 1.3% chance of exploitation in the next 30 days.

A type confusion vulnerability could be triggered when resolving the "typeof" unary operator in Facebook Hermes prior to v0.10.0. Note that this is only exploitable if the application using Hermes permits evaluation of untrusted JavaScript. Hence, most React Native applications are not affected.

Affected products

• Facebook Hermes: before 0.10.0 (fixed in 0.10.0)

Published 2021-12-13. Last modified 2026-06-17.