Mozilla Firefox up to 143.0 on iOS Cookie information disclosure

CVSS Meta Temp Score
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Current Exploit Price (≈)
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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$0-$5k0.00

Summaryinfo

A vulnerability was found in Mozilla Firefox up to 143.0 on iOS. It has been classified as problematic. This impacts an unknown function of the component Cookie Handler. This manipulation causes information disclosure. This vulnerability is handled as CVE-2025-10859. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Mozilla Firefox up to 143.0 on iOS. It has been declared as problematic. Affected by this vulnerability is an unknown code block of the component Cookie Handler. The manipulation with an unknown input leads to a information disclosure vulnerability. The CWE definition for the vulnerability is CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. As an impact it is known to affect confidentiality. The summary by CVE is:

Cookie storage for non-HTML temporary documents was being shared incorrectly with normal browsing content, allowing information from private tabs to escape Incognito mode even after the user closed all tabs This vulnerability affects Firefox for iOS < 143.1.

The advisory is shared at bugzilla.mozilla.org. This vulnerability is known as CVE-2025-10859 since 09/22/2025. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/30/2025). MITRE ATT&CK project uses the attack technique T1592 for this issue.

Upgrading to version 143.1 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2025-31731). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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Version

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Website

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

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

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Firefox 143.1

Timelineinfo

09/22/2025 CVE reserved
09/30/2025 +8 days Advisory disclosed
09/30/2025 +0 days VulDB entry created
09/30/2025 +0 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2025-10859 (🔒)
GCVE (CVE): GCVE-0-2025-10859
GCVE (VulDB): GCVE-100-326401
EUVD: 🔒

Entryinfo

Created: 09/30/2025 16:28
Updated: 09/30/2025 16:38
Changes: 09/30/2025 16:28 (57), 09/30/2025 16:38 (1)
Complete: 🔍
Cache ID: 216:599:103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

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