Mozilla Firefox was updated to the 4.0.1 security release.

MFSA 2011-12: Mozilla developers identified and fixed
several memory safety bugs in the browser engine used in
Firefox and other Mozilla-based products. Some of these
bugs showed evidence of memory corruption under certain
circumstances, and we presume that with enough effort at
least some of these could be exploited to run arbitrary
code. Credits

Mozilla developers Boris Zbarsky, Gary Kwong, Jesse
Ruderman, Michael Wu, Nils, Scoobidiver, and Ted Mielczarek
reported memory safety issues which affected Firefox 4.
(CVE-2011-0079)

Mozilla developer Scoobidiver reported a memory safety
issue which affected Firefox 4 and Firefox 3.6
(CVE-2011-0081)

Ian Beer reported a crash that affected Firefox 4, Firefox
3.6 and Firefox 3.5. (CVE-2011-0070)

MFSA 2011-17 / CVE-2011-0068: Two crashes that could
potentially be exploited to run malicious code were found
in the WebGL feature and fixed in Firefox 4.0.1. In
addition the WebGLES libraries could potentially be used to
bypass a security feature of recent Windows versions. The
WebGL feature was introduced in Firefox 4; older versions
are not affected by these issues.

Nils reported that the WebGLES libraries in the Windows
version of Firefox were compiled without ASLR protection.
An attacker who found an exploitable memory corruption flaw
could then use these libraries to bypass ASLR on Windows
Vista and Windows 7, making the flaw as exploitable on
those platforms as it would be on Windows XP or other
platforms.

Mozilla researcher Christoph Diehl reported a potentially
exploitable buffer overflow in the WebGLES library

Yuri Ko reported a potentially exploitable overwrite in the
WebGLES library to the Chrome Secuity Team. We thank them
for coordinating with us on this fix.

MFSA 2011-18 / CVE-2011-1202: Chris Evans of the Chrome
Security Team reported that the XSLT generate-id() function
returned a string that revealed a specific valid address of
an object on the memory heap. It is possible that in some
cases this address would be valuable information that could
be used by an attacker while exploiting a different memory
corruption but, in order to make an exploit more reliable
or work around mitigation features in the browser or
operating system.