CVE-2025-10859

MEDIUM 4.0

Data stored in cookies for non-HTML content while browsing Incognito could be viewed after closing private tabs

CVSS Score

4.0

EPSS Score

0.0%

EPSS Percentile

0th

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.

Vendor	mozilla
Product	firefox for ios
Ecosystems	Browser JavaScript
Industries	Technology
Published	Sep 30, 2025
Last Updated	Apr 13, 2026

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Affected Versions

Mozilla / Firefox for iOS

All versions affected

References

NVD ↗ CVE.org ↗ EPSS Data ↗

bugzilla.mozilla.org: https://bugzilla.mozilla.org/show_bug.cgi?id=1684624 mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-79/

Credits

Muneaki Nishimura