Mozilla Thunderbird Vulnerabilities

9 advisories affecting Mozilla Thunderbird

9

Total CVEs

7

Critical

2

High

CVE-2026-7321

Apr 28, 2026

Critical (9.6)

Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Thunderbird 150, and Firefox ESR 140.10.1....

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CVE-2026-6785

Apr 26, 2026

High (8.1)

Memory safety bugs present in Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149. Some of these bugs showed evidence of memory corruption and we presume that...

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CVE-2026-6786

Apr 26, 2026

High (8.1)

Memory safety bugs present in Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149. Some of these bugs showed evidence of memory corruption and we presume that with enough effort ...

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CVE-2026-6748

Apr 21, 2026

Critical (9.8)

Uninitialized memory in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10....

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CVE-2026-6768

Apr 21, 2026

Critical (9.8)

Mitigation bypass in the Networking: Cookies component. This vulnerability was fixed in Firefox 150 and Thunderbird 150....

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CVE-2026-6771

Apr 21, 2026

Critical (9.8)

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10....

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CVE-2026-5731

Apr 7, 2026

Critical (9.8)

Memory safety bugs present in Firefox ESR 115.34.0, Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evidence of memory corruption and w...

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CVE-2026-5734

Apr 7, 2026

Critical (9.8)

Memory safety bugs present in Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evidence of memory corruption and we presume that with en...

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CVE-2026-5735

Apr 7, 2026

Critical (9.8)

Memory safety bugs present in Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been expl...

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