CVE-2026-8973: Memory safety bugs fixed in Thunderbird 151

Published May 19, 2026
·
Updated

Memory safety bugs present in Firefox 150. 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.

Other sources

Memory safety bugs present in Thunderbird 150. 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.

— Mozilla

Affected Software

4 affected componentsFixes available
Mozilla Firefox<151
151
Mozilla Thunderbird<151
151
Mozilla Firefox<151.0.0
Mozilla Thunderbird<151.0.0

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 151
  2. Upgrade

    Upgrade Firefox to a version that resolves this vulnerability.

    Fixed in 151
  3. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 151

Event History

May 19, 2026
CVE Published
via Mozilla·12:00 AM
Data Sourced
via Mozilla·12:00 AM
DescriptionSeverityAffected Software
Updated
via Mozilla·12:00 AM
DescriptionAffected Software
CVE Published
via MITRE·12:30 PM
Data Sourced
via MITRE·12:30 PM
Description
Data Sourced
via Red Hat·02:03 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·02:16 PM
DescriptionSeverityWeaknessAffected Software
Apr 28, 58520
Event
via FIRST·08:22 AM

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-2026-8973?

CVE-2026-8973 is classified as a critical vulnerability due to the potential for memory corruption leading to arbitrary code execution.

2

How do I fix CVE-2026-8973?

To fix CVE-2026-8973, update to Mozilla Firefox or Thunderbird version 151 or later.

3

What products are affected by CVE-2026-8973?

CVE-2026-8973 affects Mozilla Firefox versions earlier than 151 and Mozilla Thunderbird versions earlier than 151.

4

Can CVE-2026-8973 be exploited?

Yes, CVE-2026-8973 includes memory safety bugs that could potentially be exploited for arbitrary code execution.

5

Is there a workaround for CVE-2026-8973?

There is no specific workaround for CVE-2026-8973; the best mitigation is to update the affected software.

Company

Resources

Contact

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