Harness swiftly responded to the Log4Shell vulnerability, identified in the Java logging library log4j, by implementing a comprehensive patching strategy across its SaaS environment and delegates without impacting performance or availability. The vulnerability, which allowed remote code execution, affected versions 2.0 to 2.14.1 of log4j. Harness's incident response involved multiple departments, leading to quick identification and patching of affected components, prioritizing external-facing services and ensuring stability across their Kubernetes clusters on Google Cloud Platform. Despite initial patches, further updates were required due to newly discovered bypasses and vulnerabilities, resulting in the deployment of log4j 2.16.0 and later 2.17.0 to mitigate additional risks. Harness maintains vigilance by continuously monitoring for updates and ensuring the security of its environments.