Information Disclosure in Plane (CVE-2026-105639)
Summary
Vulnerability in Plane (CVE-2026-105639). Successful exploitation can lead to full system takeover. Exploitable via GET /api/users/me/workspaces/invitations/. Mitigation: upgrade to 1.4.0 or later.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-105639 has been found in Plane.
Attackers can target a specific entry point like GET /api/users/me/workspaces/invitations/ over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 9.8/10.
What to do: upgrade Plane to 1.4.0 or later.
If unsure, ask your IT team or search "Plane CVE-2026-105639" on the vendor's site.
CVE-2026-105639 (Plane) — CWE-200 / CVSS v3 9.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: GET /api/users/me/workspaces/invitations/
Patched: 1.4.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Information disclosure (CWE-200) exists in Plane. Attackers reach the vulnerable code path via GET /api/users/me/workspaces/invitations/ without authentication.
Check the vendor advisory for the affected versions of Plane. Attack surface: GET /api/users/me/workspaces/invitations/.
Severity: Critical (CVSS 9.8/10). Successful exploitation can lead to full system takeover.
Update to 1.4.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual GET /api/users/me/workspaces/invitations/ requests with malformed payloads or SQL meta-characters. Run grep -r 'Plane' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'Plane' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Planeを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'GET /api/users/me/workspaces/invitations/' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
GET /api/users/me/workspaces/invitations/への異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Apply patch patch
Upgrade Plane to 1.4.0ステージング環境で 1.4.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 2 で見つけた異常検知の続報チェックを含めること。
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4Post-deployment verification verify
Replay attack against GET /api/users/me/workspaces/invitations/ on staging to confirm patch closes the vectorパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。