Information Disclosure in Firefox for iOS Affects Private Browsing Sessions
CVE-2025-10859

4MEDIUM

Key Information:

Vendor

Mozilla
Status
Firefox For iOS
Vendor
CVE Published:
30 September 2025

What is CVE-2025-10859?

A vulnerability exists in Firefox for iOS where cookie storage for non-HTML temporary documents incorrectly shares information with standard browsing contexts. This flaw allows sensitive data from private browsing sessions to be accessible even after closing all tabs, compromising user privacy. The issue affects Firefox for iOS versions earlier than 143.1, posing a significant risk to users engaged in confidential activities.

Affected Version(s)

Firefox for iOS < 143.1

References

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

CVSS V3.1

Score:
4
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
Low
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Muneaki Nishimura
JSON
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CVE-2025-10859 : Information Disclosure in Firefox for iOS Affects Private Browsing Sessions