CVE-2026-53899 | Firefox for iOS used partial domain matching when attaching … | CVSS 6.5 MEDIUM

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.

Metadata

CVE ID: CVE-2026-53899
State: PUBLISHED
Assigner: mozilla
Reserved: 2026-06-11 06:20 UTC
Published: 2026-06-16 11:53 UTC
Last updated: 2026-06-16 15:44 UTC
Primary CWE: CWE-345
CWE-345 Insufficient Verification of Data Authenticity
Vendor / Product: Mozilla / Firefox for iOS
Sources: cve.org · NVD

Severity & Metrics

6.5 MEDIUM CVSS 3.1

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

SSVC — CISA Coordinator

Exploitation: none
Automatable: yes
Tech. Impact: partial

Affected products (1)

Vendor	Product	Platform	Versions
Mozilla	Firefox for iOS	—	152.0 ≤ *

Weakness (CWE)

CWE	Source	Description
CWE-345	adp	CWE-345 Insufficient Verification of Data Authenticity

CVSS scores (1)

Score	Severity	Version	Source	Vector
6.5	MEDIUM	3.1	adp	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References (2)