CVE-2020-26970

HighCVSS 8.8/10Last modified Jun 17, 2026

Description

When reading SMTP server status codes, Thunderbird writes an integer value to a position on the stack that is intended to contain just one byte. Depending on processor architecture and stack layout, this leads to stack corruption that may be exploitable. This vulnerability affects Thunderbird < 78.5.1.

Metrics

CVSS 3.1 8.8/10CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Weakness enumeration

CWE-787

Affected software

Vendor	Product	Versions
Mozilla	Thunderbird	< 78.5.1

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1677338Issue Tracking, Permissions Required, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-53/Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1677338Issue Tracking, Permissions Required, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-53/Vendor Advisory

Timeline

Published: Dec 9, 2020
Last modified: Jun 17, 2026
NVD status: Modified

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