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.
"GitLab has remediated an issue in the GitLab AI Gateway that, under certain conditions, could have allowed an authenticated user with Duo Agent Platform access to escape the prompt template sandbox via a specially crafted flow configuration, leading to arbitrary command execution on the AI Gateway," the company explained in a Friday advisory.
GitLab released versions 19.2.4, 19.3.2, and 19.4.1 to address this vulnerability for Self-Hosted AI Gateway users and said that customers using a GitLab-hosted AI Gateway are already protected and do not need to take action.
"These versions contain a critical security fix for GitLab Self-Hosted AI Gateway, and we strongly recommend that all GitLab Self-Managed customers with GitLab Self-Hosted AI Gateway installations update to one of these versions immediately," it said. "We have conducted targeted outreach to Self-Hosted AI Gateway customers prior to this release post with this guidance."