CVE-2026-8390: Use-after-free in the JavaScript: WebAssembly component

Published May 12, 2026
·
Updated

Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150.0.3.

Affected Software

3 affected componentsFixes available
Mozilla Firefox<150.0.3
Mozilla Firefox<150.0.3
150.0.3
Mozilla Firefox<150.0.3

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 150.0.3
  2. Upgrade

    Upgrade Mozilla Firefox to a version that resolves this vulnerability.

    Fixed in 150.0.3

Event History

May 12, 2026
CVE Published
via Mozilla·12:00 AM
Data Sourced
via Mozilla·12:00 AM
DescriptionSeverityAffected Software
CVE Published
via MITRE·12:36 PM
Data Sourced
via MITRE·12:36 PM
Description
Data Sourced
via Red Hat·02:02 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·02:17 PM
DescriptionSeverityWeaknessAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

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Frequently Asked Questions

1

What is the severity of CVE-2026-8390?

CVE-2026-8390 has a high severity rating due to the potential exploitation of a use-after-free vulnerability in the JavaScript: WebAssembly component.

2

How do I fix CVE-2026-8390?

To fix CVE-2026-8390, update Mozilla Firefox to version 150.0.3 or later.

3

What are the effects of CVE-2026-8390 if exploited?

If exploited, CVE-2026-8390 can lead to remote code execution or application crashes.

4

Which versions of Firefox are affected by CVE-2026-8390?

CVE-2026-8390 affects Firefox versions prior to 150.0.3.

5

Is there a workaround for CVE-2026-8390?

There is no effective workaround for CVE-2026-8390; the best action is to update to the fixed version.

Company

Resources

Contact

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