Adobe has released critical security patches fixing 13 vulnerabilities in Adobe Reader and Acrobat versions 9.1.1 for Windows and Macintosh.

Adobe describes many of the vulnerabilities as critical, because they allow crafted PDF documents to inject malicious code into a system and run it. Most of the bugs again affect the JBIG2 filter.

Adobe’s security bulletin also announced that several publicly undocumented security bugs have been patched with these updates.