CVE-2020-26974

Mozilla: Incorrect cast of StyleGenericFlexBasis resulted in a heap use-after-free

Published Jan 7, 2021 CVSS 3.1 · 8.8 High EPSS 1.5% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-2496-1 firefox-esr security update
Debian DLA Debian DLA DLA-2497-1 thunderbird security update
Debian DSA Debian DSA DSA-4813-1 firefox-esr security update
Debian DSA Debian DSA DSA-4815-1 thunderbird security update
EUVD EUVD EUVD-2020-19498 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.
Ubuntu USN Ubuntu USN USN-4671-1 Firefox vulnerabilities
Ubuntu USN Ubuntu USN USN-4701-1 Thunderbird vulnerabilities
History

No history.

Weaknesses

Sources

Status
PUBLISHED
Assigner
mozilla
Published
Updated
Aug 4, 2024, 4:03 PM
Reserved
Oct 12, 2020, 12:00 AM
Status
Modified
Published
Jan 7, 2021, 2:15 PM
Modified
Jun 17, 2026, 3:08 AM
Severity
Important
Public date
Dec 15, 2020, 12:00 AM