CVE-2026-3889: Spoofing issue in Thunderbird

Published Mar 24, 2026
·
Updated

Spoofing issue in Thunderbird. This vulnerability affects Thunderbird < 149 and Thunderbird < 140.9.

Other sources

Spoofing issue in Thunderbird. This vulnerability was fixed in Thunderbird 149 and Thunderbird 140.9.

— MITRE

Affected Software

5 affected componentsFixes available
Mozilla Thunderbird<149, <140.9
Mozilla Thunderbird<140.9
140.9
Mozilla Thunderbird<149
149
Mozilla Thunderbird<140.9.0
Mozilla Thunderbird<149.0

Event History

Mar 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·08:27 PM
Data Sourced
via MITRE·08:27 PM
Description
Data Sourced
via Red Hat·09:02 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·09:16 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-2026-3889?

The severity of CVE-2026-3889 is classified as a spoofing vulnerability.

2

How do I fix CVE-2026-3889?

To fix CVE-2026-3889, upgrade Thunderbird to version 149 or later, or to version 140.9 or later.

3

Which versions of Thunderbird are affected by CVE-2026-3889?

CVE-2026-3889 affects Thunderbird versions prior to 149 and prior to 140.9.

4

What kind of attack does CVE-2026-3889 enable?

CVE-2026-3889 enables spoofing attacks that can mislead users within Thunderbird.

5

Who is impacted by CVE-2026-3889?

Users of Thunderbird versions older than 149 and 140.9 are at risk due to CVE-2026-3889.

Company

Resources

Contact

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