CVE-2020-12419: Use After Free
Last updated 25 August 2025
Other sources
When processing callbacks that occurred during window flushing in the parent process, the associated window may die; causing a use-after-free condition. This could have led to memory corruption and a potentially exploitable crash.
— Mozilla
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Thunderbirdto a version that resolves this vulnerability.Fixed in 78 - Upgrade
Upgrade
Thunderbirdto a version that resolves this vulnerability.Fixed in 68.10 - Upgrade
Upgrade
Firefoxto a version that resolves this vulnerability.Fixed in 78 - Upgrade
Upgrade
Firefox ESRto a version that resolves this vulnerability.Fixed in 68.10 - Upgrade
Upgrade
debian/firefoxto a version that resolves this vulnerability.Fixed in 149.0.2-1 - Upgrade
Upgrade
debian/firefox-esrto a version that resolves this vulnerability.Fixed in 115.14.0esr-1~deb11u1Fixed in 140.9.1esr-1~deb11u1Fixed in 128.14.0esr-1~deb12u1Fixed in 140.9.1esr-1~deb12u1Fixed in 140.8.0esr-1~deb13u1Fixed in 140.9.1esr-1~deb13u1Fixed in 140.9.1esr-1 - Upgrade
Upgrade
debian/thunderbirdto a version that resolves this vulnerability.Fixed in 1:115.12.0-1~deb11u1Fixed in 1:140.9.1esr-1~deb11u1Fixed in 1:140.6.0esr-1~deb12u1Fixed in 1:140.9.1esr-1~deb12u1Fixed in 1:140.8.0esr-1~deb13u1Fixed in 1:140.9.1esr-1~deb13u1Fixed in 1:140.9.0esr-1Fixed in 1:140.9.1esr-1 - Upgrade
Upgrade
alpine/firefoxto a version that resolves this vulnerability.Fixed in 78.0-r0 - Upgrade
Upgrade
alpine/firefox-esrto a version that resolves this vulnerability.Fixed in 68.10.0-r0 - Upgrade
Upgrade
alpine/librewolfto a version that resolves this vulnerability.Fixed in 78.0-r0 - Upgrade
Upgrade
alpine/mozjs68to a version that resolves this vulnerability.Fixed in 68.10.0-r0 - Upgrade
Upgrade
alpine/thunderbirdto a version that resolves this vulnerability.Fixed in 68.10.0-r0 - Upgrade
Upgrade
Thunderbirdto a version that resolves this vulnerability.Fixed in 68.10.0
Event History
Parent advisories
This vulnerability appears in the following advisories.
Peer vulnerabilities
Found alongside the following vulnerabilities.
Frequently Asked Questions
What is the severity of CVE-2020-12419?
The severity of CVE-2020-12419 is critical.
Which software versions are affected by CVE-2020-12419?
Firefox ESR < 68.10, Firefox < 78, and Thunderbird < 68.10 are affected by CVE-2020-12419.
What is the vulnerability description of CVE-2020-12419?
CVE-2020-12419 is a use-after-free vulnerability in the parent process of Firefox and Thunderbird, which could lead to memory corruption and potentially exploitable crashes.
How can I fix CVE-2020-12419?
To fix CVE-2020-12419, update your Firefox or Thunderbird to version 78.0.1 or later.
Where can I find more information about CVE-2020-12419?
You can find more information about CVE-2020-12419 in the following references: [Bugzilla](https://bugzilla.mozilla.org/show_bug.cgi?id=1643874), [Mozilla Security Advisories](https://www.mozilla.org/en-US/security/advisories/mfsa2020-24/).