CVE-2026-8948
Same-origin policy bypass in Firefox DOM Networking
Publication date: 2026-05-19
Last updated on: 2026-05-20
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 151.0.0 (exc) |
| mozilla | thunderbird | to 151.0.0 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-942 | The product uses a web-client protection mechanism such as a Content Security Policy (CSP) or cross-domain policy file, but the policy includes untrusted domains with which the web client is allowed to communicate. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is a same-origin policy bypass in the DOM Networking component of Mozilla Firefox. The same-origin policy is a critical security mechanism that restricts how documents or scripts loaded from one origin can interact with resources from another origin. A bypass means that this restriction can be circumvented, potentially allowing malicious scripts to access or manipulate data from other origins.
This issue was fixed in Firefox version 151.
How can this vulnerability impact me? :
By bypassing the same-origin policy, an attacker could potentially access sensitive information or perform unauthorized actions by exploiting the DOM Networking component. This could lead to data leakage, unauthorized data manipulation, or other security breaches within the browser environment.
What immediate steps should I take to mitigate this vulnerability?
The vulnerability was fixed in Firefox 151. To mitigate this vulnerability, you should update your Firefox browser to version 151 or later.