CVE-2024-7530Public exploitNetwork attack vector

Browser crash via finalized coverage-script dereference

Published Aug 6, 2024 · Updated Aug 8, 2024

Use-after-free in Mozilla Firefox before 129 allows context-dependent attackers to crash the browser during JavaScript code-coverage collection. During incremental garbage collection, scriptCountsMap retains a finalized BaseScript whose poisoned ScriptSourceObject is dereferenced when coverage collection is disabled. Triggering the flaw requires Firefox’s JavaScript Debugger coverage interface; the demonstrated consequence is a process crash, not published code execution.

CVSS severity8.8
High
EPSS probability0.38%
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 Mozilla Firefox before 129 allows context-dependent attackers to crash the browser during JavaScript code-coverage collection. During incremental garbage collection, scriptCountsMap retains a finalized BaseScript whose poisoned ScriptSourceObject is dereferenced when coverage collection is disabled. Triggering the flaw requires Firefox’s JavaScript Debugger coverage interface; the demonstrated consequence is a process crash, not published code execution.

The record

CVE
CVE-2024-7530
Published
Aug 6, 2024
Updated
Aug 8, 2024
Vendor
Mozilla
Product
Firefox
Classifications
CWE-416, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 6, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 8, 2024Record 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 <129
  2. Affected versionversion=unspecified <129

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=0 <129; version=unspecified <129

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
9.8CISA-ADPCVSS: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 exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

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

Technologies

Your stack

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Your stack

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