PT-2026-49700 · Mozilla · Firefox For Ios

Muneaki Nishimura · CVE-2026-53899 · Published 2026-06-16 · Updated 2026-06-17

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Name of the Vulnerable Software and Affected Versions Firefox for iOS versions prior to 152.0

Description Firefox for iOS used partial domain matching when attaching cookies to PDF requests. This behavior allows a malicious site hosted on a suffix domain to receive cookies belonging to the target site, leading to cookie leakage.

Recommendations Update to version 152.0.

Fix

Insufficient Verification of Data Authenticity

Weakness Enumeration

CWE-345

Related Identifiers

CVE-2026-53899

Affected Products

Firefox For Ios

References · 8

• https://nvd.nist.gov/vuln/detail/CVE-2026-53899 · Security Note
• https://mozilla.org/security/advisories/mfsa2026-56 · Vendor Advisory
• https://twitter.com/VulmonFeeds/status/2066889837383221559 · Twitter Post
• https://bugzilla.mozilla.org/show_bug.cgi?id=2042909 · Note
• https://twitter.com/infoflowcloud/status/2066981824354504841 · Twitter Post
• https://t.me/CVEtracker/56995 · Telegram Post
• https://t.me/cveNotify/169510 · Telegram Post
• https://twitter.com/CVEnew/status/2066980921757302877 · Twitter Post