CVE-2026-6771
Mitigation Bypass in Firefox DOM Security 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 | From 140.0 (inc) to 140.10.0 (exc) |
| mozilla | thunderbird | From 140.0 (inc) to 140.10.0 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-288 | The product requires authentication, but the product has an alternate path or channel that does not require authentication. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is a mitigation bypass in the DOM (Document Object Model) security component of Mozilla Firefox. It means that a security measure designed to protect the DOM was circumvented, potentially allowing an attacker to exploit the browser in ways that were previously prevented.
The issue was addressed and fixed in Firefox version 150 and Firefox ESR 140.10.
How can this vulnerability impact me? :
Exploitation of this vulnerability could allow an attacker to bypass security protections in the browser's DOM, potentially leading to unauthorized actions such as executing malicious scripts, accessing sensitive information, or compromising the integrity of web content.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, update Firefox to version 150 or later, or Firefox ESR to version 140.10 or later, where the issue has been fixed.