Embodiments of the present invention provide an approach to repair vulnerabilities (e.g., security vulnerabilities) in images (e.g., application images) in a networked computing environment (e.g., a cloud computing environment). Specifically, an image is checked for vulnerabilities using a database of known images and/or vulnerabilities. If a vulnerability is found, a flexible/elastic firewall is established around the image so as to isolate the vulnerability. Once the firewall has been put in place, the vulnerability can be repaired by a variety of means such as upgrading the image, quarantining the image, discarding the image, and/or generating a new image. Once the image has been repaired, the firewall can be removed.