Today, Magento published a software update that covers security issues.
SUPEE-6788 Technical Details (magento.org)
Magento Enterprise Edition 220.127.116.11, Community Edition 18.104.22.168 and the patch bundle SUPEE-6788 address several security issues. Unfortunately, addressing these issues required some changes that may possibly break backward compatibility with customizations or extensions.
Install New Security Patch Immediately
Today, we are releasing a new security patch (SUPEE-6788), Enterprise Edition 22.214.171.124 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 Enterprise Edition and Magento Community Edition release notes.
Our Website Maintenance Department will be in contact with our clients regarding this upgrade.