What’s Vulnerable › Vulnerabilities

CVE-2021-24045

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-12-13 · updated 2026-06-17
• Weakness: CWE-843

Description

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

How to fix

Upgrade to a fixed version: Facebook Hermes 0.10.0. Check the vendor advisory for mitigations.

References

• https://github.com/facebook/hermes/commit/55e1b2343f4deb1a1b5726cfe1e23b2068217ff2
• https://www.facebook.com/security/advisories/cve-2021-24045
• https://github.com/facebook/hermes/commit/55e1b2343f4deb1a1b5726cfe1e23b2068217ff2
• https://www.facebook.com/security/advisories/cve-2021-24045

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