CVE-2026-0884
Unknown Unknown - Not Provided
Use-After-Free in Firefox JavaScript Engine Enables Exploits

Publication date: 2026-01-13

Last updated on: 2026-04-13

Assigner: Mozilla Corporation

Description
Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.
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Meta Information
Published
2026-01-13
Last Modified
2026-04-13
Generated
2026-06-16
AI Q&A
2026-01-14
EPSS Evaluated
2026-06-14
NVD
CVE-2026-0884
Affected Vendors & Products
Showing 2 associated CPEs
Vendor Product Version / Range
mozilla firefox to 147 (exc)
mozilla firefox_esr to 140.7 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
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Executive Summary

This vulnerability is a use-after-free bug in the JavaScript Engine component of Firefox versions prior to 147 and Firefox ESR versions prior to 140.7. A use-after-free occurs when a program continues to use memory after it has been freed, which can lead to unexpected behavior or exploitation by attackers.

Impact Analysis

The vulnerability has a high impact with a CVSS score of 9.8, meaning it can be exploited remotely without user interaction to cause high confidentiality, integrity, and availability impacts. This could allow attackers to execute arbitrary code, take control of the affected system, or cause crashes and denial of service.

Mitigation Strategies

To mitigate this vulnerability, update Firefox to version 147 or later, or Firefox ESR to version 140.7 or later, as these versions include fixes for the use-after-free vulnerability in the JavaScript Engine component. [2]

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