SSRF (Server-Side Request Forgery) in github.com/gotenberg/gotenberg/v8 (CVE-2026-42596)
Summary
SSRF in github.com/gotenberg/gotenberg/v8 (CVE-2026-42596). Confidential information can be exposed externally. Exploitable via POST /upload. Mitigation: upgrade to 8.32.0 or later.
Original description
The description as published by the source.
Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.31.0, the default deny-lists used by Gotenberg's downloadFrom feature and webhook feature are bypassable. Because the filter is regex-based and case-sensitive, an unauthenticated attacker can supply URLs such as http://[::ffff:127.0.0.1]:... and reach loopback or private HTTP services that the default deny-list is intended to block. This crosses a real security boundary because an external caller can force the server to make outbound requests to internal-only targets. This vulnerability is fixed in 8.31.0.
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-2026-42596 has been found in github.com/gotenberg/gotenberg/v8.
Attackers can target a specific entry point like POST /upload over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 9.4/10.
What to do: upgrade github.com/gotenberg/gotenberg/v8 to 8.32.0 or later.
If unsure, ask your IT team or search "github.com/gotenberg/gotenberg/v8 CVE-2026-42596" on the vendor's site.
CVE-2026-42596 (github.com/gotenberg/gotenberg/v8) — CWE-918 / CVSS v3 9.4
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: POST /upload / POST /events / downloadFrom / webhook
Patched: 8.32.0 — 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 github.com/gotenberg/gotenberg/v8. Attackers reach the vulnerable code path via POST /upload without authentication.
Check the vendor advisory for the affected versions of github.com/gotenberg/gotenberg/v8. Attack surface: POST /upload / POST /events / downloadFrom / webhook.
Severity: Critical (CVSS 9.4/10). Confidential information can be exposed externally.
Update to 8.32.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual POST /upload requests with malformed payloads or SQL meta-characters. Run grep -r 'github.com/gotenberg/gotenberg/v8' . 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 'github.com/gotenberg/gotenberg/v8' . | 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
github.com/gotenberg/gotenberg/v8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 'POST /upload' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /upload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 github.com/gotenberg/gotenberg/v8 to 8.32.0ステージング環境で 8.32.0 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。
-
4Post-deployment verification verify
Replay attack against POST /upload 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。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com