Vulnerability Report

CVE-2026-53899

Title: Partial Domain Matching Cookie Vulnerability in Firefox for iOS

Other

Proof Of Concept

No public PoC currently indexed for CVE-2026-53899.

CWE Category NVD-CWE-noinfo

Published Date Jun 16, 2026

Modified Date Jun 17, 2026

Exploit Status Not Found

Score 6.5 CVSS v

Exploit Probability (EPSS)

0.10%

Vulnerability Summary

CVE-2026-53899: 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.

Impacted Vendors

mozilla 1

Reference Links

https://bugzilla.mozilla.org/show_bug.cgi?id=2042909 https://www.mozilla.org/security/advisories/mfsa2026-56/

CVSS v3.1

Source Entity 134c704f-9b21-4f2e-91b3-4a467353bcc0

Severity MEDIUM

6.5

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

UNCHANGED

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

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-53899 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

June 17, 2026 MODIFIED

Vulnerability data updated via NVD.

June 16, 2026 MODIFIED

Vulnerability data updated via NVD.

June 16, 2026 MODIFIED

Vulnerability data updated via NVD.

June 16, 2026 MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK

Complexity LOW

Privileges N/A

Interaction NONE

CVSS Vector String


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

Affected Stack

No specific products linked.