CVE-2024-8385Network attack vector

Code execution via WASM type confusion

Published Sep 3, 2024 · Updated Sep 6, 2024

Type confusion in Mozilla Firefox before 130, Firefox ESR before 128.2, and Thunderbird before 128.2 allows remote attackers to execute code via WASM. Mozilla identifies inconsistent handling of StructFields and ArrayTypes in WASM as the type-confusion locus but does not disclose the exact invalid operation. Exploitation requires attacker-controlled WASM in a browser or browser-like context; Thunderbird disables scripting while reading mail, limiting ordinary email exposure.

CVSS severity9.8
Critical
EPSS probability0.57%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Type confusion in Mozilla Firefox before 130, Firefox ESR before 128.2, and Thunderbird before 128.2 allows remote attackers to execute code via WASM. Mozilla identifies inconsistent handling of StructFields and ArrayTypes in WASM as the type-confusion locus but does not disclose the exact invalid operation. Exploitation requires attacker-controlled WASM in a browser or browser-like context; Thunderbird disables scripting while reading mail, limiting ordinary email exposure.

The record

CVE
CVE-2024-8385
Published
Sep 3, 2024
Updated
Sep 6, 2024
Vendor
Mozilla
Product
Firefox
Classifications
CWE-843, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 3, 2024CVE publishedPublication date reported by the CVE source.
  2. Sep 6, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0 <130
  2. Affected versionversion=unspecified <130

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=0 <130; version=unspecified <130
Mozilla · Thunderbirdversion=unspecified <128.2
Mozilla · Firefox ESRversion=0 <128.2; version=unspecified <128.2

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8NIST NVDCVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-843Access of Resource Using Incompatible Type ('Type Confusion')
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo