CVE-2026-100778
Received Received - Intake

DOM Use-After-Free Vulnerability in Firefox

Publication date: 2026-09-29

Last updated on: 2026-09-29

Assigner: Mozilla Corporation

Description
Sandbox escape due to use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.

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Meta Information

Published
2026-09-29
Last Modified
2026-09-29
Generated
2026-09-29
AI Q&A
2026-09-29
EPSS Evaluated
N/A
NVD
CVE-2026-100778
EUVD
EUVD-2026-88930

Affected Vendors & Products

Showing 4 associated CPEs
Vendor Product Version / Range
mozilla firefox 153.4
mozilla firefox 157
mozilla firefox 115.42
mozilla firefox 140.17

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This is a sandbox escape vulnerability caused by a use-after-free error in Firefox's DOM: Core & HTML components. A use-after-free occurs when a program continues to use a pointer after freeing the memory it points to, potentially allowing attackers to execute arbitrary code or escape browser sandbox restrictions.

Impact Analysis

This vulnerability could allow malicious websites or code to break out of the browser's security sandbox. This might enable attackers to access sensitive data, install malware, or perform unauthorized actions on your system, potentially leading to system compromise or data theft.

Mitigation Strategies

Update Firefox ESR to version 153.4 or later, Firefox to version 157 or later, Firefox ESR 115.42 or later, or Firefox ESR 140.17 or later to patch the use-after-free vulnerability in the DOM: Core & HTML component.

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