Microsoft has released the December Patch Tuesday security bulletin, with a total of six alerts. The most significant issue covered is a serious vulnerability in the Internet Explorer browser software.

Three of the six bulletins were marked as ‘Critical’, with vulnerabilities in Microsoft Project and Internet Authentication Services fixed alongside the now customary cumulative patch covering a selection of problems recently spotted with IE. All could lead to remote execution of code.

Less serious, but still labelled ‘Important’, were fixes for the Local Security Authority Subsystem Service (LSASS), Active Directory and text conversion features in WordPad and Office applications.

Once again Adobe has followed Micorosoft’s lead by releasing its own set of updates on the same date – a serious flaw in the Flash player software, again described as ‘critical’, has been patched, and further alerts have been issued about Illustrator products.

The official Microsoft bulletins are available here, with a summary from SANS here and some commentary in The Register here. Adobe’s alerts are here. As always, VB advises readers to ensure all systems are fully patched and up-to-date as soon as possible.