VDB-364674 · CVE-2026-8963 · Nessus 316445

Mozilla Firefox up to 150 Web Speech authentication spoofing

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.
5.8	$0-$5k	0.00

Summaryinfo

A vulnerability, which was classified as problematic, was found in Mozilla Firefox up to 150. This affects an unknown part of the component Web Speech. The manipulation results in an unknown weakness. This vulnerability is cataloged as CVE-2026-8963. The attack may be launched remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Mozilla Firefox up to 150. Affected is some unknown functionality of the component Web Speech. CWE is classifying the issue as CWE-290. This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks. This is going to have an impact on integrity. CVE summarizes:

Spoofing issue in the Web Speech component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

The advisory is available at bugzilla.mozilla.org. This vulnerability is traded as CVE-2026-8963 since 05/19/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 06/17/2026).

The vulnerability scanner Nessus provides a plugin with the ID 316445 (Linux Distros Unpatched Vulnerability : CVE-2026-8963), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 151 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (316445) and CERT Bund (WID-SEC-2026-1606). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

Debian Linux
Amazon Linux 2
Red Hat Enterprise Linux
SUSE Linux
Oracle Linux
IGEL OS
SUSE openSUSE
RESF Rocky Linux
Mozilla Firefox
Mozilla Firefox ESR
Mozilla Thunderbird

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: 5.9
VulDB Meta Temp Score: 5.8

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

ADP CISA Base Score: 7.5
ADP CISA Vector: 🔒

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: Authentication spoofing
CWE: CWE-290 / CWE-287
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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

Nessus ID: 316445
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-8963

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Firefox 151

Timelineinfo

05/19/2026 Advisory disclosed
05/19/2026 +0 days CVE reserved
05/19/2026 +0 days VulDB entry created
06/17/2026 +29 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2026-8963 (🔒)
GCVE (CVE): GCVE-0-2026-8963
GCVE (VulDB): GCVE-100-364674
CERT Bund: WID-SEC-2026-1606 - Mozilla Firefox und Thunderbird: Mehrere Schwachstellen

Entryinfo

Created: 05/19/2026 15:56
Updated: 06/17/2026 19:43
Changes: 05/19/2026 15:56 (54), 05/23/2026 13:39 (14), 05/23/2026 18:20 (2), 06/17/2026 19:43 (7)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.