CVE-2020-26974

HIGH

Firefox <84, Thunderbird <78.6, Firefox ESR <78.6 - Memory Corruption

Title source: llm
STIX 2.1

Description

When flex-basis was used on a table wrapper, a StyleGenericFlexBasis object could have been incorrectly cast to the wrong type. This resulted in a heap user-after-free, memory corruption, and a potentially exploitable crash. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.

References (4)

Core 4
Core References
Permissions Required x_refsource_misc
https://bugzilla.mozilla.org/show_bug.cgi?id=1681022

Scores

CVSS v3 8.8
EPSS 0.0076
EPSS Percentile 73.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Details

CWE
CWE-787
Status published
Products (3)
mozilla/firefox < 84.0
mozilla/firefox_esr < 78.6.0
mozilla/thunderbird < 78.6.0
Published Jan 07, 2021
Tracked Since Feb 18, 2026