Mozilla Firefox up to 115.43/153.5/158 HTTP isolation

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.
6.0$5k-$25k0.32

Summaryinfo

A vulnerability has been found in Mozilla Firefox up to 115.43/153.5/158 and classified as critical. Affected by this vulnerability is an unknown functionality of the component HTTP. This manipulation causes isolation. The identification of this vulnerability is CVE-2026-117966. It is possible to initiate the attack remotely. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical was found in Mozilla Firefox up to 115.43/153.5/158. Affected by this vulnerability is an unknown part of the component HTTP. The manipulation with an unknown input leads to a isolation vulnerability. The CWE definition for the vulnerability is CWE-653. The product does not properly compartmentalize or isolate functionality, processes, or resources that require different privilege levels, rights, or permissions. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Site isolation issue in the Networking: HTTP component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, and Firefox ESR 153.6.

It is possible to read the advisory at bugzilla.mozilla.org. This vulnerability is known as CVE-2026-117966 since 10/27/2026. 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. 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 10/27/2026).

Upgrading to version 115.44, 153.6 or 159 eliminates this vulnerability.

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

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
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: Isolation
CWE: CWE-653
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
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 115.44/153.6/159

Timelineinfo

10/27/2026 Advisory disclosed
10/27/2026 +0 days CVE reserved
10/27/2026 +0 days VulDB entry created
10/27/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2026-117966 (🔒)
GCVE (CVE): GCVE-0-2026-117966
GCVE (VulDB): GCVE-100-427339

Entryinfo

Created: 10/27/2026 15:59
Changes: 10/27/2026 15:59 (57)
Complete: 🔍
Cache ID: 216::103

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

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