The IMAP Client, as used in mutt 1.4.1 and Balsa 2.0.10, allows remote malicious IMAP servers to cause a denial of service and possibly execute arbitrary code via certain large mailbox size values that cause either integer signedness errors or integer overflow errors.

The IMAP Client for Sylpheed 0.8.11 allows remote malicious IMAP servers to cause a denial of service (crash) via certain large literal size values that cause either integer signedness errors or integer overflow errors.