# CVE-2026-104978: Plane authorization bypass in project invitation endpoints

Source: https://junglewise.ai/threats/cve-2026-104978-plane-is-an-open-source-project-management-tool-prior-to-1-4-0  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-05. Updated: 2026-10-05  
License: CC BY 4.0 with a link back

CVE-2026-104978 · Severity: high · CVSS 8.2 · Published 2026-10-05

Plane is an open-source project management tool that allows teams to collaborate on projects. Prior to version 1.4.0, its project invitation system lacked proper authentication and authorization checks, allowing an attacker to accept project invitations on behalf of other users by knowing only public information like the workspace slug and project ID. An attacker could register an account using an invited email address and then claim access to the workspace and project without authorization.

Technologies: [Plane](https://junglewise.ai/threats/technologies/plane-plane). Vendors: [Plane](https://junglewise.ai/threats/vendors/plane).

## Quick answers

**Is CVE-2026-104978 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-104978 being exploited in the wild.

**How severe is CVE-2026-104978?** High severity, with a CVSS score of 8.2, published 5 October 2026.

**Which products and versions are affected?** Plane before 1.4.0.

**Is there a fix for CVE-2026-104978?** Yes: fixed in 1.4.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-104978 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-104978?** Check whether you run Plane at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 1.4.0

## Technical details

The vulnerability exists in Plane's project invitation endpoints, which failed to validate authentication tokens and user identity when accepting or rejecting invitations. An unauthenticated attacker could accept a project invitation by submitting only the invitee's email address, workspace slug, and project ID. The fix (version 1.4.0) enforces token validation against the invitation token, requires an authenticated session, and validates the authenticated user's email matches the invited email, mirroring the workspace join endpoint's validation logic.

## Affected products

- Plane Plane before 1.4.0

## Timeline

- 2026-10-05: disclosed

## References

- [https://github.com/makeplane/plane/commit/14a4c22f94eac1582439e41112213f976c6a6cf7](https://github.com/makeplane/plane/commit/14a4c22f94eac1582439e41112213f976c6a6cf7)
- [https://github.com/makeplane/plane/pull/9308](https://github.com/makeplane/plane/pull/9308)

## Related threats

- [Plane project management missing authorization checks](https://junglewise.ai/threats/cve-2026-102985-plane-is-an-open-source-project-management-tool-in-1-3-1-and)
- [Plane order_by injection in issue-listing endpoints](https://junglewise.ai/threats/cve-2026-102988-plane-is-an-open-source-project-management-tool-prior-to-1-4-0)
- [Plane stored XSS in comments and intake descriptions](https://junglewise.ai/threats/cve-2026-102982-plane-is-an-open-source-project-management-tool-prior-to-1-4-0)
- [Plane workspace invitation token disclosure and hijack](https://junglewise.ai/threats/cve-2026-102981-plane-is-an-open-source-project-management-tool-prior-to-1-4-0)
- [Plane hardcoded Django SECRET_KEY in community deployments](https://junglewise.ai/threats/cve-2026-105641-plane-is-an-open-source-project-management-tool-prior-to-1-4-0)