CVE-2026-105639
CRITICAL 9.8Plane 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.
Severe if exploited (CVSS 9.8), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.4%chance of exploitation in 30 days · 33rd percentile
Impact if exploited
9.8CVSS 3.1 · CRITICAL
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
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Data snapshot:
Weakness (CWE)
- CWE-200: : Exposure of Sensitive Information to an Unauthorized Actor
- CWE-287: : Improper Authentication
- CWE-639: : Authorization Bypass Through User-Controlled Key
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References and research data (JSON)
All CVSS metrics
- CRITICAL 9.8 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CRITICAL 9.8 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References
Advisories
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-92595 EUVD · EUVD-2026-92595
Technical & other
- https://github.com/makeplane/plane/security/advisories/GHSA-4vj8-p63v-8p24 CVE record · GitHub_M · Updated 2026-10-05T18:10:35.787Z
NVD · CVE-2026-105639 · Updated 2026-10-06T15:17:13.803 - https://github.com/makeplane/plane/pull/9297 CVE record · GitHub_M · Updated 2026-10-05T18:10:35.787Z
NVD · CVE-2026-105639 · Updated 2026-10-06T15:17:13.803 - https://github.com/makeplane/plane/commit/6220ba990b2276a1a1979d1d5df68f650b8b47ad CVE record · GitHub_M · Updated 2026-10-05T18:10:35.787Z
NVD · CVE-2026-105639 · Updated 2026-10-06T15:17:13.803 - https://github.com/makeplane/plane/releases/tag/v1.4.0 CVE record · GitHub_M · Updated 2026-10-05T18:10:35.787Z
NVD · CVE-2026-105639 · Updated 2026-10-06T15:17:13.803