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TI-2026-67864 Aliases CVE-2026-105639

Workspace invitation hijack in Plane lets attackers join as others

Priority MEDIUM 49CWE-200Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Information disclosure, Security bypass
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-200 and CWE-287.

Summary

Plane before 1.4.0 creates a logged-in account for any email submitted at signup, without checking that the submitter owns the address. Its invitation listing also returns the invitation token that the join endpoint requires (CWE-639). An unauthenticated remote attacker who knows a target's email can register with that address, read the target's pending invitations and accept one as the target, joining the workspace at the invited role.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00394 33rd percentileScored 2026-11-07
Fix Fixed plane (makeplane): 1.4.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
makeplaneplanebefore 1.4.01.4.0Patch availableCNA
  • plane Vendormakeplane Affected before 1.4.0 Fixed in 1.4.0 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:plane:plane:*:*:*:*:*:*:*:*——makeplane
  • cpe:2.3:a:plane:plane:*:*:*:*:*:*:*:* Versions — — ·makeplane

Remediation

Upgrade Plane to version 1.4.0, which fixes this issue.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

  • Fix · CNA plane (makeplane) Fixed in 1.4.0

Timeline

  1. 2026-10-05 Threatist record created from CVE-2026-105639
  2. 2026-10-06 CISA SSVC decision points changed

References

Other 4

  • TI-2026-67866 Hardcoded secret keys in Plane community deployments CVSS 3.1CRITICAL 9.8
  • TI-2026-67865 Account takeover in Plane via unverified OAuth email matching CVSS 3.1CRITICAL 9.1
  • TI-2026-67863 Plane magic-code login lacks rate limiting, allowing OTP brute force CVSS 3.1CRITICAL 9.1
  • TI-2024-32097 Plane allows server side request forgery via /_next/image endpoint CVSS 3.1CRITICAL 9.3
  • TI-2026-67862 Cross-project asset hijacking in Plane allows file takeover CVSS 3.1CRITICAL 9.6
  • TI-2026-67861 Server-side request forgery in Plane webhook delivery via redirects CVSS 3.1CRITICAL 9.9
See all 65 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences