Pillow before 2.7.0 allows remote attackers to cause a denial of service via a compressed text chunk in a PNG image that has a large size when it is decompressed.
https://www.djangoproject.com/weblog/2015/jan/02/pillow-security-release/
https://github.com/python-pillow/Pillow/pull/1060
http://www.securityfocus.com/bid/77758
http://www.oracle.com/technetwork/topics/security/bulletinjul2015-2511963.html
http://pillow.readthedocs.org/releasenotes/2.7.0.html
http://lists.opensuse.org/opensuse-updates/2015-04/msg00056.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-January/148442.html