CVE-2026-105639 — Plane: Pre-auth workspace invitation hijack via email-squat and self-served invitation token leak in Plane
Plane is an open-source project management tool. Prior to 1.4.0, Plane's signup flow creates a logged-in User row for any submitted email without an out-of-band ownership check,…
Published: 2026-10-05 · CVSS: 9.8 · CVSS 3.1
Plane is an open-source project management tool. Prior to 1.4.0, Plane's signup flow creates a logged-in User row for any submitted email without an out-of-band ownership check, while User.email is unique=True. The authenticated user can call GET /api/users/me/workspaces/invitations/, which returns each WorkspaceMemberInvite whose email matches request.user.email. WorkSpaceMemberInviteSerializer uses fields = "all", exposing the token that protects the invitation join endpoint. An unauthenticated attacker who knows a target's email can register an account using that address, enumerate pending invitations, and accept an invitation as the target, joining a workspace at the invited role. The term pre-auth describes the attacker's initial state: the attacker has no credential before signup, while the enumeration and join requests use the session created by that signup. This issue is fixed in 1.4.0.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7