Unrestricted File Upload in budibase (CVE-2026-46426)
Summary
Vulnerability in budibase (CVE-2026-46426). Confidential information can be exposed externally. Exploitable via POST /api/attachments/process. Mitigation: upgrade to 3.38.2 or later.
Original description
The description as published by the source.
Budibase is an open-source low-code platform. Prior to 3.38.2, the file upload endpoint POST /api/attachments/process does not enforce active-content restrictions for authenticated users. The checks for dangerous file extensions are conditionally wrapped inside if (isPublicUser) or if (isPublicUser || !env.SELF_HOSTED), meaning any authenticated builder can upload executable web content — SVG files with inline tags, HTML pages with JavaScript, .js modules — which are then stored in the object store (MinIO/S3) with their correct MIME types. When the resulting signed URL is opened by any app user, the browser executes the payload. Impact is persistent stored XSS over all application end users. This vulnerability is fixed in 3.38.2.
Source: GitHub Security Advisories (Global) 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-2026-46426 has been found in budibase.
Attackers can target a specific entry point like POST /api/attachments/process over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.6/10.
What to do: upgrade budibase to 3.38.2 or later.
If unsure, ask your IT team or search "budibase CVE-2026-46426" on the vendor's site.
CVE-2026-46426 (budibase) — CWE-434 / CVSS v3 7.6
Attack vector: remote (network-reachable)
Attack surface: POST /api/attachments/process / POST /api/attachments/ / POST /api/global/auth/default/login / html
Patched: 3.38.2 — 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.
A vulnerability (CWE-434) exists in budibase. Attackers reach the vulnerable code path via POST /api/attachments/process.
Check the vendor advisory for the affected versions of budibase. Attack surface: POST /api/attachments/process / POST /api/attachments/ / POST /api/global/auth/default/login / html.
Severity: High (CVSS 7.6/10). Confidential information can be exposed externally.
Update to 3.38.2.
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 /api/attachments/process requests with malformed payloads or SQL meta-characters. Run grep -r 'budibase' . 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 'budibase' . | 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
budibase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 /api/attachments/process' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /api/attachments/process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 budibase to 3.38.2ステージング環境で 3.38.2 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 /api/attachments/process 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
- web github.com