Vulnerability · Published Oct 5, 2026 · Assigned by GitHub_M
CVE-2026-105639Plane: Pre-auth workspace invitation hijack via email-squat and self-served invitation token leak in Plane
Critical 9.8
In plain English
A critical-severity information exposure in plane from makeplane. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities).
Official description
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.
Affected products (as reported)
Weakness: CWE-200, CWE-287, CWE-639 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References
- https://github.com/makeplane/plane/security/advisories/GHSA-4vj8-p63v-8p24 x_refsource_CONFIRM
- https://github.com/makeplane/plane/pull/9297 x_refsource_MISC
- https://github.com/makeplane/plane/commit/6220ba990b2276a1a1979d1d5df68f650b8b47ad x_refsource_MISC
- https://github.com/makeplane/plane/releases/tag/v1.4.0 x_refsource_MISC