Read the docs
TI-2021-06359 Aliases CVE-2021-24044GHSA-7mhc-prgv-r3q4

Type confusion in Meta Hermes

Priority MEDIUM 45CWE-843Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-843 and the CVSS impact.

Summary

By passing invalid javascript code where await and yield were called upon non-async and non-generator getter/setter functions, Hermes would invoke generator functions and error out on invalid await/yield positions. This could result in segmentation fault as a consequence of type confusion error, with a low chance of RCE. This issue affects Hermes versions prior to v0.10.0.

Why it matters now

EPSS 0.0126 69th percentileScored 2026-11-07
Fix Fixed Hermes (Facebook): 0.10.0hermes-engine (npm): 0.10.0

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
MetaHermesbefore 0.10.00.10.0Patch availableCNA
—hermes-engine (npm)before 0.10.00.10.0Patch availableGHSA-7mhc-prgv-r3q4
  • Hermes VendorMeta Affected before 0.10.0 Fixed in 0.10.0 Patch available CNA
  • hermes-engine (npm) Vendor— Affected before 0.10.0 Fixed in 0.10.0 Patch available GHSA-7mhc-prgv-r3q4

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:facebook:hermes:*:*:*:*:*:*:*:*before 0.10.0VulnerableMeta
  • cpe:2.3:a:facebook:hermes:*:*:*:*:*:*:*:* Versions before 0.10.0 Vulnerable ·Meta

Remediation

  • Fix · CNA Hermes (Facebook) Fixed in 0.10.0
  • Fix · GHSA-7mhc-prgv-r3q4 hermes-engine (npm) Fixed in 0.10.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-24044
  2. 2026-10-03 Alias added: GHSA-7mhc-prgv-r3q4

References

Advisory 2

Other 1

  • TI-2023-14306 Use after free in Meta Hermes CVSS 3.1CRITICAL 9.8
  • TI-2023-12661 Use after free in Meta Hermes CVSS 3.1CRITICAL 9.8
  • TI-2023-11181 Type confusion in Meta Hermes CVSS 3.1CRITICAL 9.8
  • TI-2023-09388 Type confusion in Meta Hermes CVSS 3.1CRITICAL 9.8
  • TI-2023-09387 Out-of-bounds write in Meta Hermes CVSS 3.1CRITICAL 9.8
  • TI-2020-01841 A logic vulnerability when handling the SaveGeneratorLong instruction in Facebook Hermes… CVSS 3.1CRITICAL 9.8
See all 19 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences