CVE-2026-100762

Undergoing Analysis Undergoing Analysis - In Progress

DOM Use-After-Free Vulnerability in Firefox

Publication date: 2026-09-29

Last updated on: 2026-10-13

Assigner: Mozilla Corporation

Description

Sandbox escape due to use-after-free in the DOM: Content Processes component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-29

Last Modified

2026-10-13

Generated

2026-10-19

AI Q&A

2026-09-29

EPSS Evaluated

2026-10-18

NVD

CVE-2026-100762

EUVD

EUVD-2026-88914

Affected Vendors & Products

Vendor	Product	Version / Range
mozilla	firefox	From 154.0.0 (inc) to 157.0.0 (exc)
mozilla	thunderbird	From 154.0 (inc) to 157.0 (exc)
mozilla	firefox	to 115.42.0 (exc)
mozilla	thunderbird	to 140.17.0 (exc)
mozilla	thunderbird	From 141.0 (inc) to 153.4.0 (exc)
mozilla	firefox	From 116.0.0 (inc) to 140.17.0 (exc)
mozilla	firefox	From 141.0.0 (inc) to 153.4.0 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-416	The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Attack-Flow Graph

Executive Summary

This is a sandbox escape vulnerability caused by a use-after-free issue in the DOM: Content Processes component of Firefox. A use-after-free occurs when a program continues to use memory after it has been freed, potentially allowing attackers to execute arbitrary code or escape browser sandbox restrictions.

Detection Guidance

This vulnerability is specific to Firefox browsers and was patched in versions Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17. To detect it, check your Firefox version using about:support in the browser or run 'firefox --version' in the terminal. If your version is older than the patched ones, update immediately.

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 with the same privileges as the browser.

Compliance Impact

The provided CVE data does not specify how this vulnerability impacts compliance with standards like GDPR or HIPAA. The description only mentions a sandbox escape vulnerability due to use-after-free in the DOM: Content Processes component, fixed in specific Firefox versions.

Mitigation Strategies

Update Firefox to a patched version: Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, or Firefox ESR 140.17 or later.

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