CVE-2026-53900 | Firefox for iOS preserved cookies set on the initial PDF req… | CVSS 4.3 MEDIUM

Description

Firefox for iOS preserved cookies set on the initial PDF request across cross-origin HTTP redirects in TemporaryDocument, allowing a malicious site to inject arbitrary cookies into requests to an unrelated target domain. This vulnerability was fixed in Firefox for iOS 152.0.

Metadata

CVE ID: CVE-2026-53900
State: PUBLISHED
Assigner: mozilla
Reserved: 2026-06-11 06:20 UTC
Published: 2026-06-16 11:53 UTC
Last updated: 2026-06-16 14:37 UTC
Primary CWE: CWE-345
CWE-345 Insufficient Verification of Data Authenticity
Vendor / Product: Mozilla / Firefox for iOS
Sources: cve.org · NVD

Severity & Metrics

4.3 MEDIUM CVSS 3.1

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

SSVC — CISA Coordinator

Exploitation: none
Automatable: no
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
CWE-384	adp	CWE-384 Session Fixation

CVSS scores (1)

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

References (2)