GitLab warned customers today to immediately patch a critical AI Gateway vulnerability that could let attackers run arbitrary commands on vulnerable instances.

AI Gateway is a service that gives access to AI-native GitLab Duo features. While GitLab operates its own cloud-based AI Gateway instance used by GitLab.com, GitLab Self-Managed, and GitLab Dedicated, users can also deploy their own self-hosted instances on GitLab Self-Managed through GitLab Duo Self-Hosted.

Tracked as CVE-2026–90970, this security flaw stems from an improper neutralization weakness and can let attackers with basic privileges and Duo Agent Platform access execute arbitrary commands on unpatched instances.