CVE-2026-6784: Memory safety bugs fixed in Firefox 150 and Thunderbird 150

Published Apr 21, 2026
·
Updated

Memory safety bugs present in Firefox 149 and Thunderbird 149. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.

Affected Software

4 affected componentsFixes available
Mozilla Firefox<150
150
Mozilla Thunderbird<150
150
Mozilla Firefox<150.0
Mozilla Thunderbird<150.0

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
  2. Upgrade

    Upgrade firefox to a version that resolves this vulnerability.

    Fixed in 150
  3. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 150

Event History

Apr 21, 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·12:41 PM
Data Sourced
via MITRE·12:41 PM
Description
Data Sourced
via NVD·01:16 PM
DescriptionSeverityWeaknessAffected Software
Data Sourced
via Red Hat·02:01 PM
DescriptionSeverityAffected 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 are the memory safety bugs in CVE-2026-6784?

CVE-2026-6784 describes memory safety bugs in Firefox 149 and Thunderbird 149 that potentially allow exploitation leading to arbitrary code execution.

2

How can I resolve CVE-2026-6784?

To fix CVE-2026-6784, upgrade to Firefox 150 or Thunderbird 150 to benefit from the applied memory safety fixes.

3

What is the severity rating of CVE-2026-6784?

CVE-2026-6784 has a severity rating of high, with a CVSS score of 7.5.

4

What is the potential impact of exploiting CVE-2026-6784?

Exploiting CVE-2026-6784 could lead to memory corruption and potentially allow attackers to execute arbitrary code.

5

Which products are affected by CVE-2026-6784?

The affected products are Mozilla Firefox and Mozilla Thunderbird, specifically versions prior to 150.

Company

Resources

Contact

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