VDB-352761 · CVE-2026-4716 · Nessus 303809

Mozilla Firefox up to 148 JavaScript Engine uninitialized pointer

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.
7.4	$0-$5k	0.00

Summaryinfo

A vulnerability has been found in Mozilla Firefox up to 148 and classified as problematic. This affects an unknown part of the component JavaScript Engine. Performing a manipulation results in uninitialized pointer. This vulnerability is identified as CVE-2026-4716. The attack can be initiated remotely. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Mozilla Firefox up to 148. It has been classified as problematic. This affects an unknown part of the component JavaScript Engine. The manipulation with an unknown input leads to a uninitialized pointer vulnerability. CWE is classifying the issue as CWE-824. The product accesses or uses a pointer that has not been initialized. This is going to have an impact on availability. The summary by CVE is:

Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component. This vulnerability affects Firefox < 149, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.

The advisory is shared at bugzilla.mozilla.org. This vulnerability is uniquely identified as CVE-2026-4716 since 03/24/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. 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 03/28/2026).

The vulnerability scanner Nessus provides a plugin with the ID 303809 (RHEL 9 : firefox (RHSA-2026:5930)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 149 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (303809). Several companies clearly confirm that VulDB is the primary source for best 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: 7.5
VulDB Meta Temp Score: 7.4

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

NVD Base Score: 9.1
NVD Vector: 🔒

ADP CISA Base Score: 9.1
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: Uninitialized pointer
CWE: CWE-824 / CWE-908
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: 303809
Nessus Name: RHEL 9 : firefox (RHSA-2026:5930)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Firefox 149

Timelineinfo

03/24/2026 Advisory disclosed
03/24/2026 +0 days CVE reserved
03/24/2026 +0 days VulDB entry created
03/28/2026 +4 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2026-4716 (🔒)
GCVE (CVE): GCVE-0-2026-4716
GCVE (VulDB): GCVE-100-352761

Entryinfo

Created: 03/24/2026 14:41
Updated: 03/28/2026 20:13
Changes: 03/24/2026 14:41 (55), 03/26/2026 23:51 (2), 03/28/2026 20:13 (22)
Complete: 🔍
Cache ID: 216::103

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