CVE-2024-4764Network attack vector

Browser crash via concurrent audio-input ownership

Published May 14, 2024 · Updated Aug 1, 2024

Use-after-free in Firefox WebRTC before 126 allows attackers to crash the browser when multiple threads claim a newly connected audio input. Competing WebRTC threads can both claim the same new input, so teardown frees an audio object while another consumer still uses it. Reproduction requires multiple active WebRTC consumers and an audio-device connection change; Mozilla's public case used two Meet tabs and AirPods on macOS.

CVSS severity9.8
Critical
EPSS probability0.57%
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 Firefox WebRTC before 126 allows attackers to crash the browser when multiple threads claim a newly connected audio input. Competing WebRTC threads can both claim the same new input, so teardown frees an audio object while another consumer still uses it. Reproduction requires multiple active WebRTC consumers and an audio-device connection change; Mozilla's public case used two Meet tabs and AirPods on macOS.

The record

CVE
CVE-2024-4764
Published
May 14, 2024
Updated
Aug 1, 2024
Vendor
Mozilla
Product
Firefox
Classifications
CWE-416
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 14, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 1, 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=126* <126
  2. Affected versionversion=unspecified <126

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=126* <126; version=unspecified <126

Published CVSS scores

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.

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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.

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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