CVE-2024-6601Network attack vector

Cross-origin permission gain via feature-policy race

Published Jul 9, 2024 · Updated Oct 30, 2025

A permission race in Mozilla Firefox before 128, Firefox ESR before 115.13, and Thunderbird before 128 lets attackers gain top-origin permissions. FeaturePolicy can initialize before the new window context becomes current, causing a cross-origin container to receive the default policy instead of its inherited restrictions. Exploitation requires winning that document-loading timing window and grants site capabilities assigned to the top-level origin; no code execution is reported.

CVSS severity4.7
Medium
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A permission race in Mozilla Firefox before 128, Firefox ESR before 115.13, and Thunderbird before 128 lets attackers gain top-origin permissions. FeaturePolicy can initialize before the new window context becomes current, causing a cross-origin container to receive the default policy instead of its inherited restrictions. Exploitation requires winning that document-loading timing window and grants site capabilities assigned to the top-level origin; no code execution is reported.

The record

CVE
CVE-2024-6601
Published
Jul 9, 2024
Updated
Oct 30, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-367, T1203
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Jul 9, 2024CVE publishedPublication date reported by the CVE source.
  2. Oct 30, 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=unspecified <128

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

Mozilla · Firefoxversion=unspecified <128
Mozilla · Thunderbirdversion=unspecified <115.13; version=unspecified <128
Mozilla · Firefox ESRversion=unspecified <115.13

Published CVSS scores

4.7CISA-ADPCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
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

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Your stack

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