Adobe has confessed that once again its software could give hackers a route into users' PCs and is advising that people should immediately update their Reader and Acrobat software to the latest iterations.
Using a faulty PDF to force a back door into people's PCs has long been the tool of choice for the average cyber-criminal and Tuesday brought an admission from Adobe that they had another security issue with its two major PDF programmes.
The threat, which applies equally to Macs and Windows PCs, was classified as critical, despite the insistence that no software has yet been found by Adobe that would use the vulnerability.
The news came on the same day as Microsoft's regular patch Tuesday brought a weighty 31 fixes.
The current crop included patches for IE, Windows and Office.