The security update for wordpress in DSA 3328 contained a regression. The patch for issue CVE-2015-5622 was faulty. A new package version has been released that backs this patch out pending resolution of the problem.
For the stable distribution (jessie), these problems have been fixed in version 4.1+dfsg-1+deb8u3.
We recommend that you upgrade your wordpress packages.
Further information about Debian Security Advisories, how to apply these updates to your system and frequently asked questions can be found at: https://www.debian.org/security/