A number of vulnerabilities were found and fixed in Mozilla Firefox.
For details please consult the references below.
Impact
The most severe vulnerability involves enticing a user to visit a
malicious website, crashing the browser and executing arbitrary code
with the rights of the user running the application.
Workaround
There is no known workaround at this time.
Resolution
All Mozilla Firefox users should upgrade to the latest version:
Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org.