CVE-2026-6751
Uninitialized Memory Vulnerability in Firefox Web Codecs Component
Publication date: 2026-04-21
Last updated on: 2026-04-22
Assigner: Mozilla Corporation
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| mozilla | firefox | to 150.0 (exc) |
| mozilla | firefox | to 140.10.0 (exc) |
| mozilla | thunderbird | From 140.0 (inc) to 140.10.0 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-457 | The code uses a variable that has not been initialized, leading to unpredictable or unintended results. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability involves uninitialized memory in the Audio/Video: Web Codecs component of Mozilla Firefox. Uninitialized memory means that the software may use memory that has not been properly set up, which can lead to unpredictable behavior or security issues.
The issue was addressed and fixed in Firefox version 150 and Firefox ESR 140.10.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, update your Firefox browser to version 150 or later, or Firefox ESR to version 140.10 or later, where the issue has been fixed.
How can this vulnerability impact me? :
This vulnerability involves uninitialized memory in the Audio/Video: Web Codecs component of Firefox. It has a CVSS v3.1 base score of 7.3, indicating a high severity. The impact includes potential confidentiality, integrity, and availability losses, meaning an attacker could potentially access sensitive information, alter data, or disrupt service without requiring privileges or user interaction.