Today, we are releasing a new security patch (SUPEE-6788) and Community Edition 126.96.36.199 to address over 10 issues identified through our comprehensive security program, including remote code execution and information leak vulnerabilities. This patch is unrelated to the recent Guruincsite malware issue. There are no confirmed reports of attacks related to these issues to-date, but it is important that you deploy the patch in order to protect your store. More information about the patch is provided in the Magento Security Center and in the Magento Community Edition release notes.
This patch breaks backward compatibility in ways that can affect your extensions or customizations (see notesfor details). For example, certain updates to admin routing can make improperly coded extensions and customizations inaccessible from the admin panel. We expect that many extensions and customizations will be affected by this change, so we are releasing the patch with it included, but turned off. This lets you immediately benefit from the rest of the patch, while also giving you time to update your code before turning on the admin routing change.
We recommend that you first test the code in a non-production environment with the admin routing change turned on. If it works, deploy the fully-enabled patch to production. If you discover issues with accessing extensions or customizations from the admin panel, deploy the patch with the admin routing change disabled. Then work with your developer and extension providers to update impacted customizations and extensions. We urge you to turn on the admin routing change as soon as possible to protect your site from automated attacks, like the malware issue we recently experienced.