Vulnerability in @budibase/server (CVE-2026-54356)
Summary
Vulnerability in @budibase/server (CVE-2026-54356). Data can be tampered with by attackers. Exploitable via POST /api/attachments/.
Original description
The description as published by the source.
Summary
Budibase 3.39.7 allows a low-privilege authenticated published-app user with the built-in BASIC role to obtain arbitrary S3 pre-signed upload URLs backed by a workspace datasource's stored server-side credentials.
The affected endpoint is:
POST /api/attachments/:datasourceId/url
The caller can control:
bucket
key
and receives:
signedUrl
publicUrl
This lets a low-privilege published-app user mint S3 PUT URLs using server-side datasource credentials for attacker-chosen object destinations.
Steps:
- Log in as an admin user.
- Create a new app/workspace.
- In the development app context, create an S3 datasource with valid credentials.
- Publish the app.
- Create a low-privilege user with the built-in BASIC role on the published production app ID.
- Log in as that BASIC user.
- Send:
POST /api/attachments//url
with:
{"bucket":"foo","key":"bar"}
and the published app header:
x-budibase-app-id:
Observe a successful response containing:
signedUrl
publicUrl
Observed result
The following behavior:
dev BASIC request: 403 User does not have permission
app publish: SUCCESS
prod BASIC request: 200 OK
Example confirmed runtime values from the final successful run:
prodAppId: app_e6b4cdc6cd6949969a83ff11eee88c5a
datasourceId: datasource_0cec491b26a742468257c62382aa3284
publicUrl: https://foo.s3.eu-west-1.amazonaws.com/bar
The returned signedUrl contained standard AWS signing marker…
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-2026-54356 has been found in @budibase/server.
Attackers can target a specific entry point like POST /api/attachments/ over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 7.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "@budibase/server CVE-2026-54356" on the vendor's site.
CVE-2026-54356 (@budibase/server) — CWE-862 / CVSS v3 7.1
Attack vector: remote (network-reachable) / no user interaction
Attack surface: POST /api/attachments/ / PUT
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-862) exists in @budibase/server. Attackers reach the vulnerable code path via POST /api/attachments/.
Check the vendor advisory for the affected versions of @budibase/server. Attack surface: POST /api/attachments/ / PUT.
Severity: High (CVSS 7.1/10). Data can be tampered with by attackers.
Update to the patched release per vendor advisory.
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/ requests with malformed payloads or SQL meta-characters. Run grep -r '@budibase/server' . 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/server' . | 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/server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/' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /api/attachments/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。 -
3Post-deployment verification verify
Replay attack against POST /api/attachments/ 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 nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com