CSS-based exfiltration of the content from partially encrypted emails when allowing remote content. This vulnerability affects Thunderbird < 147.0.1 and Thunderbird < 140.7.1.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - CSS-based exfiltration of the content from partially encrypted emails when allowing remote content. This     vulnerability affects Thunderbird < 147.0.1 and Thunderbird < 140.7.1. (CVE-2026-0818)

Note that Nessus relies on the presence of the package as reported by the vendor.

The version of Thunderbird installed on the remote macOS or Mac OS X host is prior to 147.0.1. It is, therefore, affected by a vulnerability as referenced in the mfsa2026-07 advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of Thunderbird installed on the remote macOS or Mac OS X host is prior to 140.7.1. It is, therefore, affected by a vulnerability as referenced in the mfsa2026-08 advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of Thunderbird installed on the remote Windows host is prior to 140.7.1. It is, therefore, affected by a vulnerability as referenced in the mfsa2026-08 advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of Thunderbird installed on the remote Windows host is prior to 147.0.1. It is, therefore, affected by a vulnerability as referenced in the mfsa2026-07 advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
297038	Linux Distros Unpatched Vulnerability : CVE-2026-0818	Nessus	Misc.	medium
297035	Mozilla Thunderbird < 147.0.1	Nessus	MacOS X Local Security Checks	high
297034	Mozilla Thunderbird < 140.7.1	Nessus	MacOS X Local Security Checks	high
297033	Mozilla Thunderbird < 140.7.1	Nessus	Windows	high
297032	Mozilla Thunderbird < 147.0.1	Nessus	Windows	high

Detections

Analytics

CVE-2026-0818

medium

Tenable Plugins

medium

high

high

high

high