This advisory also applies to the corresponding versions of Kubuntu, Edubuntu, and Xubuntu.
It was discovered that PCRE did not correctly handle very long strings containing UTF8 sequences. In certain situations, an attacker could exploit applications linked against PCRE by tricking a user or automated system in processing a malicious regular expression leading to a denial of service or possibly arbitrary code execution.
Solution: The problem can be corrected by upgrading your system to the following package versions:
Ubuntu 6.06 LTS: libpcre3 7.4-0ubuntu0.6.06.2
Ubuntu 6.10: libpcre3 7.4-0ubuntu0.6.10.2
Ubuntu 7.04: libpcre3 7.4-0ubuntu0.7.04.2
Ubuntu 7.10: libpcre3 7.4-0ubuntu0.7.10.2
After a standard system upgrade you need to reboot your computer to effect the necessary changes.