Summary The shared form-view submit handler in NocoDB writes the form's "redirect_url" to "window.location.href" after a same-host check that does not validate the URL scheme. A user with "editor" role (or above) on any base can plant a "javascript:" URL in the form's "redirect_url"; when an authenticated viewer opens the share-link and submits the form, the payload executes in the NocoDB origin and can read the session token from "localStorage["nocodb-gui-v2"]". Details The vulnerable sink is in "packages/nc-gui/composables/useSharedFormViewStore.ts": - "isValidRedirectUrl" validated only "typeof === 'string'" and non-empty trim — no scheme check. - The submit branch built an anchor element, compared "anchor.host" to "window.location.host", and either pushState-reloaded (same host) or assigned "window.location.href = redirectUrl" (otherwise). - For non-network schemes such as "javascript:", "data:", "vbscript:", and "file:", "anchor.host" is the empty string, so the same-host check is false and the code falls into the external-redirect branch — executing the URL same-origin in the NocoDB tab. The "redirect_url" field is writable by any user with "editor" role on the base via the form-view PATCH endpoint, and the value is returned verbatim by the public shared-view meta endpoint, so no further privilege is required to weaponize a public form share. Impact - Same-origin script execution in the viewer's NocoDB tab. The payload runs in the NocoDB origin and can read the session token at "localStorage["nocodb-gui-v2"].token". - Action under the viewer's identity. With the token, an attacker can call authenticated APIs as the viewer, scoped to whatever workspaces, bases, and operations that viewer is permitted to use. - Single-click viewer flow. Form share-links are the intended distribution channel for forms, so the phishing surface is on-brand; the form can be configured with a single hidden pre-filled required field to reduce the viewer flow to one click. Credit This issue was reported by "@kah-ja" (https://github.com/kah-ja) ("turingpoint.de" (https://turingpoint.de)).