CVE-2026-53899

MEDIUM

Cross-origin cookies could be leaked when opening a PDF link

Title source: cna

Description

Firefox for iOS used partial domain matching when attaching cookies to PDF requests, allowing a malicious site on a suffix domain to receive cookies belonging to the target site. This vulnerability was fixed in Firefox for iOS 152.0.

References (2)

Core 2

Core References

https://bugzilla.mozilla.org/show_bug.cgi?id=2042909

https://www.mozilla.org/security/advisories/mfsa2026-56/

Scores

CVSS v3 6.5

EPSS 0.0010

EPSS Percentile 0.9%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

CISA SSVC

Vulnrichment

Exploitation none

Automatable yes

Technical Impact partial

Details

CWE

CWE-345

Status published

Products (2)

Mozilla/Firefox for iOS 152.0

mozilla/firefox_mobile < 152.0

Published Jun 16, 2026

Tracked Since Jun 16, 2026