CVE-2026-100774
Received Received - Intake

Use-after-free in Mozilla Firefox

Publication date: 2026-09-29

Last updated on: 2026-09-29

Assigner: Mozilla Corporation

Description
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-2026-100774
EUVD
EUVD-2026-88926

Affected Vendors & Products

Showing 7 associated CPEs
Vendor Product Version / Range
mozilla firefox to 153.4 (inc)
mozilla firefox 157
mozilla firefox to 115.42 (inc)
mozilla firefox to 140.17 (inc)
mozilla firefox 153.4
mozilla firefox 115.42
mozilla firefox 140.17

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Exploitability

CWE
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This is a use-after-free vulnerability in Firefox's DOM: Core & HTML component. Use-after-free occurs when a program continues to use memory after it has been freed, potentially leading to crashes or arbitrary code execution.

Detection Guidance

This vulnerability is specific to Mozilla Firefox and related ESR versions. Detection requires checking installed Firefox versions against the fixed releases: Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, or Firefox ESR 140.17. Use commands like 'firefox --version' or check package managers (e.g., 'apt list --installed | grep firefox' on Debian/Ubuntu).

Impact Analysis

An attacker could exploit this to crash your browser or run malicious code on your system. This may allow them to steal data, install malware, or take control of your device.

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. Remove or disable affected versions if updates are not immediately possible.

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