The vulnerability is an authorization flaw that allows any authenticated non-guest workspace member to erase another workspace's public custom domain. The delete handler in handleDeleteCustomDomain authorizes the caller against the supplied workspaceId but forwards the domain name to the shared Vercel project before confirming that the domain actually belongs to that workspace. The result is that a malicious member can make typebots hosted on the victim's domain unavailable.

Affected systems are all installations of TypeBot by baptisteArno that are running a version earlier than 3.18.0. This includes any self-hosted or cloud-based deployments that have not applied the 3.18.0 release notes that patch the delete logic.

The CVSS score of 6.4 indicates a moderate severity. EPSS is not available, and the vulnerability is not listed in the CISA KEV catalog. The attack vector requires authentication and likely hinges on the ability of a member to invoke the delete API with a workspaceId belonging to another tenant. An attacker would map a target workspace, craft a request with the victim's domain name, and trigger the deletion before ownership checks occur.