CVE-2019-9821: Race Condition
Published May 21, 2019
·Updated
A use-after-free vulnerability can occur in AssertWorkerThread due to a race condition with shared workers. This results in a potentially exploitable crash.
Affected Software
3 affected componentsFixes available
Mozilla Firefox<67
67
Mozilla Firefox<67.0
debian/firefox
151.0.4-1
Event History
May 21, 2019
CVE Published
12:00 AM
Jul 23, 2019
CVE Published
via MITRE·01:23 PM
Data Sourced
via MITRE·01:23 PM
DescriptionWeakness
Jan 11, 2024
Data Sourced
via Launchpad·11:34 PM
Description
Feb 19, 2026
Data Sourced
via Ubuntu·06:02 PM
RemedyDescriptionSeverityAffected Software
Jun 11, 2026
Data Sourced
via Debian·03:56 AM
DescriptionAffected Software
Peer vulnerabilities
Found alongside the following vulnerabilities.
Frequently Asked Questions
1
What is CVE-2019-9821?
CVE-2019-9821 is a use-after-free vulnerability that can occur in AssertWorkerThread due to a race condition with shared workers.
2
How does CVE-2019-9821 affect Firefox?
CVE-2019-9821 affects Firefox versions prior to 67.
3
What is the severity of CVE-2019-9821?
CVE-2019-9821 has a severity score of 8.1, which is considered high.
4
How can I fix CVE-2019-9821?
To fix CVE-2019-9821, update Firefox to version 67 or later.
5
Where can I find more information about CVE-2019-9821?
You can find more information about CVE-2019-9821 on the following references: [Bugzilla](https://bugzilla.mozilla.org/show_bug.cgi?id=1539125), [Mozilla Security Advisories](https://www.mozilla.org/en-US/security/advisories/mfsa2019-13/)