For further information on the issue in the extension powermail, please read the related advisory TYPO3-SA-2010-021 that was published today:
http://typo3.org/teams/security/security-bulletins/typo3-sa-2010-021/
TYPO3 13.1.1, 12.4.15 and 11.5.37 security releases published
The versions 13.1.1, 12.4.15 and 11.5.37 of the TYPO3 Enterprise Content Management System have just been released.