CVE-2026-2786: Use-after-free in the JavaScript Engine component

Published Feb 24, 2026
·
Updated

Use-after-free in the JavaScript Engine component. This vulnerability affects Firefox < 148 and Firefox ESR < 140.8.

Other sources

Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

— MITRE

Affected Software

8 affected componentsFixes available
Mozilla Firefox<148
148
Mozilla Firefox ESR<140.8
140.8
Mozilla Thunderbird<148
148
Mozilla Thunderbird<140.8
140.8
Mozilla Firefox<140.8.0
Mozilla Firefox<148.0
Mozilla Thunderbird<140.8.0
Mozilla Thunderbird<148.0

Event History

Feb 24, 2026
CVE Published
via Mozilla·12:00 AM
Data Sourced
via Mozilla·12:00 AM
DescriptionSeverityAffected Software
Updated
via Mozilla·12:00 AM
Affected Software
CVE Published
via MITRE·01:33 PM
Data Sourced
via MITRE·01:33 PM
Description
Data Sourced
via Red Hat·02:04 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·02:16 PM
DescriptionSeverityWeaknessAffected Software
Jan 4, 58137
Event
via FIRST·09:42 PM

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-2026-2786?

CVE-2026-2786 is classified as a high severity vulnerability due to its potential to allow arbitrary code execution.

2

How do I fix CVE-2026-2786?

To fix CVE-2026-2786, upgrade to Firefox version 148 or Firefox ESR version 140.8 or later.

3

Which versions of Firefox are affected by CVE-2026-2786?

CVE-2026-2786 affects Firefox versions earlier than 148 and Firefox ESR versions earlier than 140.8.

4

What component is impacted by CVE-2026-2786?

CVE-2026-2786 impacts the JavaScript Engine component of Firefox.

5

Is CVE-2026-2786 a remote exploit vulnerability?

Yes, CVE-2026-2786 can be exploited remotely, making it critical for users to apply the necessary updates.

Company

Resources

Contact

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