SSRF (Server-Side Request Forgery) in Plane (CVE-2026-104973)
Summary
SSRF in Plane (CVE-2026-104973). Confidential information can be exposed externally. 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, the fix for CVE-2026-30242 validates webhook IP addresses only when the webhook is created in apps/api/plane/app/serializers/webhook.py. The delivery task in apps/api/plane/bgtasks/webhook_task.py performs a separate DNS resolution when sending the request and does not validate the resolved IP address, allowing DNS rebinding to bypass the SSRF protection. 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-2026-104973 has been found in Plane.
Confidential information can be exposed externally. CVSS score: 7.6/10.
What to do: upgrade Plane to 1.4.0 or later.
If unsure, ask your IT team or search "Plane CVE-2026-104973" on the vendor's site.
CVE-2026-104973 (Plane) — CWE-918 / CVSS v3 7.6
Attack vector: remote (network-reachable) / no user interaction
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.
SSRF (CWE-918) exists in Plane.
Check the vendor advisory for the affected versions of Plane.
Severity: High (CVSS 7.6/10). Confidential information can be exposed externally.
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 request patterns matching this CVE's known IOCs. 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。 -
2Apply 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を含めること。
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3Post-deployment verification verify
Confirm patched version is live in production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。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。