Microsoft is set to unveil seven bulletins for December's Patch Tuesday release, with five of them ranked as critical.
The critical patches deal with remote code execution vulnerabilities. Microsoft's patches come as part of its monthly Patch Tuesday updates programme.
"Christmas came early from Microsoft, with five bulletins marked as remote code execution [vulnerabilities] between them covering every OS they have released since Windows XP," said Alex Horan senior product manager at Core Security.
This month's bulletins encompass every Microsoft OS that still receives frequent updates.
Microsoft has reported that the bulletins aim to fix vulnerabilities found in Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008, Windows 7, Windows Server 2008 R2, Windows 8, Windows Server 2012, and Windows RT.
Of the updates in question, Horan ranks bulletin number four as the highest priority fix. Bulletin number four focuses on a critical vulnerably found in Microsoft Exchange Server software.
"Wowser, a critical vulnerability in Exchange 2007 SP3 and 2010 SP1 & 2 - internet facing servers with remote code execution vulnerability, and email servers," continued Horan.
"You don't just randomly turn off email serves without generating howls of protest from your company to fix this one. This is my number one vulnerability in the bunch."
Among the other updates, Microsoft has released two critical patches that affect its latest Windows RT and Windows 8 platforms. The updates deal with two remote code execution vulnerabilities found in the new operating platforms.
This month's critical heavy bulletins come following a relatively light Patch Tuesday last month. In November, Microsoft released only one critical patch during its monthly updates.
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