Advisories for Npm/Unleash-Server package

Multiple authorization vulnerabilities in Unleash admin API, including a critical missing await that completely bypasses a permission check.

The change-request approval HTML email template renders fields as raw HTML. User who can create a change request can inject HTML into approval notification emails. I was not able to confirm Enterprise platform is using vulnerable code nor that it doesn't sanitize input.

The clone-feature endpoint supports copying features across projects, but it does not verify that the caller can access the source project. A user with create permissions in one project can clone a feature from another project they cannot read and then inspect the copied configuration. This vulnerability cannot be confirmed without Enterprise access. Report is based on a circumstantial evidence in the open-source repository.

Unleash scopes write permissions per project and per environment: a user with the UPDATE_FEATURE_STRATEGY permission on project A is supposed to be able to mutate activation strategies only within project A. The endpoint POST /api/admin/projects/:projectId/features/:featureName/environments/:environment/strategies/set-sort-order violates this. The RBAC middleware authorizes the request against the :projectId taken from the URL, but the handler then writes the strategy IDs supplied in the request body directly to the database by primary key, …

An unauthenticated POST to any OpenAPI-validated endpoint, including the anonymous POST /edge/validate and POST /edge/issue-token, crashes the entire Unleash server with one request body of deeply-nested JSON. When request-body validation fails, Unleash builds the error message by calling JSON.stringify on the raw offending value taken from the request body. A value nested a few thousand levels deep makes JSON.stringify recurse past the V8 call-stack limit and throw RangeError: Maximum call …

Stored markdown/link-injection (phishing-link injection) into any configured outbound notification channel (Slack legacy, MS Teams, Webhook default markdown, Datadog, New Relic), using an attacker-controlled username — no admin privilege required, only Editor on a single project, and potentially reachable through public self-signup. Secondary: loss of HTML escaping for any other reachable Mustache single-mustache placeholder process-wide until restart (increases severity of any other currently-unreached or future Mustache sink, e.g. email templates). Tertiary: …

Unleash's addon/integration subsystem lets an operator configure a webhook (and the Slack, Microsoft Teams, Datadog, and New Relic integrations) with a target url parameter. Whenever a subscribed feature-flag event fires, the Unleash server itself issues an HTTP request to that configured URL. The URL is taken verbatim from the addon's parameters.url and passed straight to the HTTP client (ky) with no validation of the host: there is no allow-list, no …