CVE-2025-10859
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-09-30

Last updated on: 2026-04-13

Assigner: Mozilla Corporation

Description
Cookie storage for non-HTML temporary documents was being shared incorrectly with normal browsing content, allowing information from private tabs to escape Incognito mode even after the user closed all tabs. This vulnerability was fixed in Firefox for iOS 143.1.
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Meta Information
Published
2025-09-30
Last Modified
2026-04-13
Generated
2026-06-16
AI Q&A
2025-09-30
EPSS Evaluated
2026-06-15
NVD
CVE-2025-10859
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
mozilla firefox From 60.9.0 (exc)
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Exploitability
CWE
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KEV
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CWE ID Description
CWE-359 The product does not properly prevent a person's private, personal information from being accessed by actors who either (1) are not explicitly authorized to access the information or (2) do not have the implicit consent of the person about whom the information is collected.
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Executive Summary

This vulnerability involves cookie storage for non-HTML temporary documents in Firefox for iOS. Cookies from private (Incognito) tabs were incorrectly shared with normal browsing sessions, allowing information from private tabs to escape Incognito mode even after all private tabs were closed. This breaks the expected isolation of private browsing. [1]

Impact Analysis

The vulnerability can lead to leakage of private browsing data into normal browsing sessions. This means sensitive information from private tabs could be accessed outside of Incognito mode, potentially exposing your private browsing activity and data to other websites or users of the device. [1]

Mitigation Strategies

Update Firefox for iOS to version 143.1 or later, as this version contains the fix for the vulnerability involving cookie storage in Incognito mode. Avoid using affected versions of Firefox for iOS until the update is applied to prevent private browsing data leakage. [1]

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