VDB-371315 · CVE-2026-53900 · GCVE-0-2026-53900

Mozilla Firefox up to 151.x on iOS cross-domain policy

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
4.1	$5k-$25k	2.00-

Summaryinfo

A vulnerability was found in Mozilla Firefox up to 151.x on iOS. It has been rated as problematic. Affected is an unknown function. The manipulation leads to cross-domain policy. This vulnerability is referenced as CVE-2026-53900. Remote exploitation of the attack is possible. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Mozilla Firefox up to 151.x on iOS. This issue affects an unknown function. The manipulation with an unknown input leads to a cross-domain policy vulnerability. Using CWE to declare the problem leads to CWE-942. The product uses a cross-domain policy file that includes domains that should not be trusted. Impacted is integrity. The summary by CVE is:

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.

It is possible to read the advisory at bugzilla.mozilla.org. The identification of this vulnerability is CVE-2026-53900 since 06/11/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 06/16/2026).

Upgrading to version 152.0 eliminates this vulnerability.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Web Browser

Vendor

Mozilla

Name

Firefox

Version

License

open-source

Website

Vendor: https://www.mozilla.org/
Product: https://www.mozilla.org/en-US/firefox/

CPE 2.3info

🔒

CPE 2.2info

🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.3
VulDB Meta Temp Score: 4.1

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Cross-domain policy
CWE: CWE-942 / CWE-346 / CWE-345
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Firefox 152.0

Timelineinfo

06/11/2026 CVE reserved
06/16/2026 +5 days Advisory disclosed
06/16/2026 +0 days VulDB entry created
06/16/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2026-53900 (🔒)
GCVE (CVE): GCVE-0-2026-53900
GCVE (VulDB): GCVE-100-371315

Entryinfo

Created: 06/16/2026 16:25
Changes: 06/16/2026 16:25 (56)
Complete: 🔍
Cache ID: 216::103