Authorization Flaw in Kestra (CVE-2026-53577)
Summary
Vulnerability in Kestra (CVE-2026-53577). Confidential information can be exposed externally. Exploitable via GET /api/v1/{tenant}/executions/{executionId}/file/preview. Mitigation: upgrade to 1.0.45 or later.
Original description
The description as published by the source.
Kestra is an open-source, event-driven orchestration platform. Prior to 1.0.45 and 1.3.21, the previewFileFromExecution endpoint (GET /api/v1/{tenant}/executions/{executionId}/file/preview) contains an access control bypass that allows any authenticated user to read output files from any other execution within the same tenant, bypassing execution-level and namespace-level isolation. This vulnerability is fixed in 1.0.45 and 1.3.21.
Source: NIST National Vulnerability Database NVD GitHub Advisory
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-2026-53577 has been found in Kestra.
Attackers can target a specific entry point like GET /api/v1/{tenant}/executions/{executionId}/file/preview over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 6.5/10.
What to do: upgrade Kestra to 1.0.45 or later.
If unsure, ask your IT team or search "Kestra CVE-2026-53577" on the vendor's site.
CVE-2026-53577 (Kestra) — CWE-863 / CVSS v3 6.5
Attack vector: remote (network-reachable) / no user interaction
Attack surface: GET /api/v1/{tenant}/executions/{executionId}/file/preview
Patched: 1.0.45 — 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.
Incorrect authorization (CWE-863) exists in Kestra. Attackers reach the vulnerable code path via GET /api/v1/{tenant}/executions/{executionId}/file/preview.
Check the vendor advisory for the affected versions of Kestra. Attack surface: GET /api/v1/{tenant}/executions/{executionId}/file/preview.
Severity: Medium (CVSS 6.5/10). Confidential information can be exposed externally.
Update to 1.0.45.
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/v1/{tenant}/executions/{executionId}/file/preview requests with malformed payloads or SQL meta-characters. Run grep -r 'Kestra' . 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 'Kestra' . | 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
Kestra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/v1/{tenant}/executions/{executionId}/file/preview' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
GET /api/v1/{tenant}/executions/{executionId}/file/preview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 Kestra to 1.0.45ステージング環境で 1.0.45 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/v1/{tenant}/executions/{executionId}/file/preview 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。
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov