CVE-2026-0884
Use-After-Free in Firefox JavaScript Engine Enables Exploits
Publication date: 2026-01-13
Last updated on: 2026-04-13
Assigner: Mozilla Corporation
Description
Description
CVSS Scores
EPSS Scores
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| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| mozilla | firefox | to 147 (exc) |
| mozilla | firefox_esr | to 140.7 (exc) |
Helpful Resources
Exploitability
| 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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.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
AI Powered Q&A
Can you explain this vulnerability to me?
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.
How can this vulnerability impact me? :
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.
What immediate steps should I take to mitigate this vulnerability?
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]