---
cve: "CVE-2026-105639"
severity: "CRITICAL"
cvss: 9.8
epss: "0.4%"
vendor: "makeplane"
kev: false
exploited: false
published: "2026-10-05 19:17:18"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-10-10T01:27:07+02:00"
---

# CVE-2026-105639

> 9.8 CRITICAL · 🧪 PoC

## Beschreibung

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.

## CNA-Record (Kanon, cvelistV5)

- CNA: **GitHub_M**
- State: PUBLISHED
- Stand: 2026-10-06 14:52:44
- CNA-CVSS: **9.8** (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **yes**
  - Technical Impact: **total**

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- 6220ba990b2276a1a1979d1d5df68f650b8b47ad (Commit)
- 917b23a6c16d93fc00cef67900eff2755e8b13f7 (Commit)

## Referenzen

- <https://github.com/makeplane/plane/security/advisories/GHSA-4vj8-p63v-8p24>
- <https://github.com/makeplane/plane/pull/9297>
- <https://github.com/makeplane/plane/commit/6220ba990b2276a1a1979d1d5df68f650b8b47ad>
- <https://github.com/makeplane/plane/releases/tag/v1.4.0>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-105639/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_