This indicates an attack attempt to exploit a Buffer Overflow vulnerability in GIMP.
The vulnerability is due to an improper boundary check condition in the application. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application or possibly cause a denial of service condition.
GIMP GIMP 2.6.7
GIMP GIMP 2.6.6
GIMP GIMP 2.6.12
GIMP GIMP 2.6.11
System Compromise: Remote attackers can gain control of vulnerable systems.
Upgrade to the latest version available from the website.