CVE-2020-12406

HighCVSS 8.8/10Last modified Jun 17, 2026

Description

Mozilla Developer Iain Ireland discovered a missing type check during unboxed objects removal, resulting in a crash. We presume that with enough effort that it could be exploited to run arbitrary code. This vulnerability affects Thunderbird < 68.9.0, Firefox < 77, and Firefox ESR < 68.9.

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-345

Affected software

Vendor	Product	Versions
Mozilla	Thunderbird	>= unspecified, < 68.9.0
Mozilla	Firefox	>= unspecified, < 77
Mozilla	Firefox ESR	>= unspecified, < 68.9

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1639590Issue Tracking, Vendor Advisory
https://usn.ubuntu.com/4421-1/Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2020-20/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-21/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-22/Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1639590Issue Tracking, Vendor Advisory
https://usn.ubuntu.com/4421-1/Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2020-20/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-21/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-22/Vendor Advisory

Timeline

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

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