Vulnerability · Published Jan 7, 2021 · Assigned by mozilla

CVE-2020-26974

High 8.8

In plain English

A high-severity security flaw in Firefox from Mozilla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.5% (higher than 75% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)8.8High
Exploit odds (30 days)1.5%top 25.1% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.20firefox84.0.1-r0ALPINE-CVE-2020-26974
Alpine:v3.21firefox84.0.1-r0ALPINE-CVE-2020-26974
Alpine:v3.22firefox84.0.1-r0ALPINE-CVE-2020-26974
Alpine:v3.23firefox84.0.1-r0ALPINE-CVE-2020-26974
Alpine:v3.20firefox-esr78.6.0-r0ALPINE-CVE-2020-26974
Alpine:v3.21firefox-esr78.6.0-r0ALPINE-CVE-2020-26974
Alpine:v3.22firefox-esr78.6.0-r0ALPINE-CVE-2020-26974
Alpine:v3.23firefox-esr78.6.0-r0ALPINE-CVE-2020-26974
Alpine:v3.21librewolf84.0.1-r0ALPINE-CVE-2020-26974
Alpine:v3.22librewolf84.0.1-r0ALPINE-CVE-2020-26974
Alpine:v3.23librewolf84.0.1-r0ALPINE-CVE-2020-26974
Alpine:v3.24librewolf84.0.1-r0ALPINE-CVE-2020-26974
Alpine:v3.20thunderbird78.6.1-r0ALPINE-CVE-2020-26974
Alpine:v3.21thunderbird78.6.1-r0ALPINE-CVE-2020-26974
Alpine:v3.22thunderbird78.6.1-r0ALPINE-CVE-2020-26974
Alpine:v3.23thunderbird78.6.1-r0ALPINE-CVE-2020-26974
Debian:12firefox-esr78.6.0esr-1DEBIAN-CVE-2020-26974
Debian:13firefox-esr78.6.0esr-1DEBIAN-CVE-2020-26974
Debian:14firefox-esr78.6.0esr-1DEBIAN-CVE-2020-26974
Debian:12thunderbird1:78.6.0-1DEBIAN-CVE-2020-26974
Debian:13thunderbird1:78.6.0-1DEBIAN-CVE-2020-26974
Debian:14thunderbird1:78.6.0-1DEBIAN-CVE-2020-26974
Ubuntu:22.04:LTSmozjs78no fix listedUBUNTU-CVE-2020-26974

Affected products (as reported)

VendorProductVersions
Mozilla Firefox unspecified – before 84
Mozilla Thunderbird unspecified – before 78.6
Mozilla Firefox ESR unspecified – before 78.6

References