CVE-2023-28081Network attack vector

Arbitrary code execution via incorrect BigInt type inference

Published May 18, 2023 · Updated Jan 21, 2025

Use-after-free in Meta Platforms Hermes before commit e6ed9c1a4b02dc219de1648f44cd808a56171b81 allows attackers to execute code via JavaScript. The optimizer omits BigInt from arithmetic result types when an Object operand returns a BigInt during valueOf coercion, producing incorrectly typed optimized bytecode. Exploitation requires Hermes to execute untrusted JavaScript; a crafted payload triggers the resulting use-after-free and arbitrary code execution.

CVSS severity9.8
Critical
EPSS probability0.89%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Meta Platforms Hermes before commit e6ed9c1a4b02dc219de1648f44cd808a56171b81 allows attackers to execute code via JavaScript. The optimizer omits BigInt from arithmetic result types when an Object operand returns a BigInt during valueOf coercion, producing incorrectly typed optimized bytecode. Exploitation requires Hermes to execute untrusted JavaScript; a crafted payload triggers the resulting use-after-free and arbitrary code execution.

The record

CVE
CVE-2023-28081
Published
May 18, 2023
Updated
Jan 21, 2025
Vendor
Meta Platforms, Inc.
Product
Hermes
Classifications
CWE-416
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 18, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <e6ed9c1a4b02dc219de1648f44cd808a56171b81

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Meta Platforms, Inc. · Hermesversion=0 <e6ed9c1a4b02dc219de1648f44cd808a56171b81

Published CVSS scores

9.8CISACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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