CVE-2026-109749: Use-after-free in the JavaScript: WebAssembly component

Published Oct 13, 2026
·
Updated

Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 158.

Affected Software

1 affected componentFixes available
Mozilla Firefox<158
158

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 158
  2. Upgrade

    Upgrade Firefox to a version that resolves this vulnerability.

    Fixed in 158

Event History

Oct 13, 2026
CVE Published
via Mozilla·12:00 AM
Data Sourced
via Mozilla·12:00 AM
DescriptionSeverityAffected Software
CVE Published
via MITRE·12:29 PM
Data Sourced
via MITRE·12:29 PM
Description
Data Sourced
via NVD·01:17 PM
DescriptionSeverityWeakness

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

Which Firefox versions are affected?

The issue was fixed in Firefox 158. The provided information does not identify the earliest affected version or any affected release range.

2

What must an attacker do to exploit this issue?

The CVSS vector indicates network-based exploitation with low attack complexity and no required privileges, but it requires user interaction. The provided information does not specify the exact user action or delivery mechanism.

3

What is the potential impact of successful exploitation?

The CVSS vector rates confidentiality and integrity impact as low, with no availability impact. The provided information does not describe the specific data exposure or modification that could result.

Company

Resources

Contact

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