CVE-2025-5266
Medium
Description
Script elements loading cross-origin resources generated load and error events which leaked information enabling XS-Leaks attacks. This vulnerability was fixed in Firefox 139, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.
SeverityMedium
CVSS4.3
Exploit probability—
Product
Mozilla Firefox
PublishedMay 27, 2025
First seenMay 27, 2025
Weakness typeCWE-200Sensitive information exposure
How to fix
Update
- mozilla firefox128.11.0, 139.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mozilla firefox | v < 128.11.0, v < 139.0 | 128.11.0, 139.0 |
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