A flaw was discovered in mutt, a text-based mailreader. A specially
crafted mail header could cause mutt to crash, leading to a denial of
service condition.
For the stable distribution (wheezy), this problem has been fixed in
version 1.5.21-6.2+deb7u3.
For the unstable distribution (sid), this problem has been fixed in
version 1.5.23-2.
We recommend that you upgrade your mutt packages.