SSRF (Server-Side Request Forgery) in Plane (CVE-2026-105636)
Summary
SSRF in Plane (CVE-2026-105636). Successful exploitation can lead to full system takeover. 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 webhook delivery task in apps/api/plane/bgtasks/webhook_task.py calls requests.post() without allow_redirects=False and does not validate redirect targets. validate_url() blocks private, loopback, link-local, and reserved addresses in the original webhook URL, but the final URL reached after one or more redirects is not checked. A user who can create a workspace can register a webhook pointing to an attacker-controlled public endpoint that returns a 302 redirect to an internal address. The Plane worker then fetches internal resources, including cloud metadata, and stores the response body in webhook_logs, where the attacker can retrieve it through the workspace webhook-logs API. 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-2026-105636 has been found in Plane.
Successful exploitation can lead to full system takeover. CVSS score: 9.9/10.
What to do: upgrade Plane to 1.4.0 or later.
If unsure, ask your IT team or search "Plane CVE-2026-105636" on the vendor's site.
CVE-2026-105636 (Plane) — CWE-918 / CVSS v3 9.9
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: Critical (CVSS 9.9/10). 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 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
-
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。
-
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。