Ubuntu Security Notice 624-1 – Tavis Ormandy discovered that the PCRE library did not correctly handle certain in-pattern options. An attacker could cause applications linked against pcre3 to crash, leading to a denial of service.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/68192/USN-624-1.txt
Source: https://packetstormsecurity.com/files/68192/Ubuntu-Security-Notice-624-1.html