It was found that the fix for CVE-2018-19758 was incomplete. That has been addressed in this update. For completeness, the description for CVE-2018-19758 follows:
A heap-buffer-overflow vulnerability was discovered in libsndfile, the library for reading and writing files containing sampled sound. This flaw might be triggered by remote attackers to cause denial of service (out of bounds read and application crash).
For Debian 7 Wheezy, these problems have been fixed in version 1.0.25-9.1+deb7u6.
We recommend that you upgrade your libsndfile packages.
Further information about Extended LTS security advisories can be found at: https://deb.freexian.com/extended-lts/