Mozilla Foundation Security Advisory 2026-39

Security Vulnerabilities fixed in Thunderbird 140.10.1

Announced
April 30, 2026
Impact
high
Products
Thunderbird
Fixed in
  • Thunderbird 140.10.1

In general, these flaws cannot be exploited through email in the Thunderbird product because scripting is disabled when reading mail, but are potentially risks in browser or browser-like contexts.

#CVE-2026-7320: Information disclosure due to incorrect boundary conditions in the Audio/Video component

Reporter
Xuehao Guo
Impact
high
References

#CVE-2026-7321: Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component

Reporter
The Mozilla Fuzzing Team
Impact
moderate
References

#CVE-2026-7322: Memory safety bugs fixed in Thunderbird ESR 140.10.1 and Thunderbird 150.0.1

Reporter
C.M.Chang, Christian Holler, Steve Fink and the Mozilla Fuzzing Team
Impact
critical
Description

Memory safety bugs present in Thunderbird ESR 140.10.0 and Thunderbird 150.0.0. 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.

References

#CVE-2026-7323: Memory safety bugs fixed in Thunderbird ESR 140.10.1 and Thunderbird 150.0.1

Reporter
Ryan Hunt, Steve Fink and the Mozilla Fuzzing Team
Impact
high
Description

Memory safety bugs present in Thunderbird ESR 140.10.0 and Thunderbird 150.0.0. 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.

References