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TI-2023-09388 Aliases CVE-2023-23557GHSA-j9jr-2qmg-cr6m

Type confusion in Meta Hermes

Priority MEDIUM 51CWE-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 · CISA ADP. Fix status from CNA. Impact type from CWE-843 and the CVSS impact.

Summary

An error in Hermes' algorithm for copying objects properties prior to commit a00d237346894c6067a594983be6634f4168c9ad could be used by a malicious attacker to execute arbitrary code via type confusion. Note that this is only exploitable in cases where Hermes is used to execute untrusted JavaScript. Hence, most React Native applications are not affected.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00891 59th percentileScored 2026-11-07
Fix Fixed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

No affected products listed by the sources yet.

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:facebook:hermes:*:*:*:*:*:*:*:*before 2023-01-10VulnerableMeta
  • cpe:2.3:a:facebook:hermes:*:*:*:*:*:*:*:* Versions before 2023-01-10 Vulnerable ·Meta

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-23557
  2. 2026-10-03 Alias added: GHSA-j9jr-2qmg-cr6m

References

Patch 2

  • 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-2023-09387 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
  • TI-2020-01823 Stack-based buffer overflow in Meta 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