Authorization Flaw in Budibase (CVE-2026-72859)
Summary
Vulnerability in Budibase (CVE-2026-72859). Data can be tampered with by attackers.
Original description
The description as published by the source.
Impact
In Budibase v3.39.4, a regression in the authorization level for the S3 attachment upload endpoint allows any BASIC app user to obtain S3 PutObject presigned URLs. The endpoint uses TABLE/WRITE permission level instead of the intended BUILDER level defined in v3.39.3. Additionally, the controller does not pin the target bucket to the datasource's configured bucket, allowing writes to any S3 bucket the stored IAM credentials can access.
Reproduction
- As a BASIC app user, discover or obtain a valid S3 datasource ID within the app
- Send a POST request:
POST /api/attachments//url
Content-Type: application/json
x-budibase-app-id:
{"bucket": "target-bucket", "key": "malicious-file.html"}
- The response contains a valid S3 PutObject presigned URL
- Use the presigned URL to upload arbitrary content to any writable S3 bucket in the IAM credential scope
Root Cause
The /api/attachments/:datasourceId/url route was changed from authorized(BUILDER) in v3.39.3 to authorized(PermissionType.TABLE, PermissionLevel.WRITE) in v3.39.4. BASIC users have TABLE/WRITE permissions by default, so they can call this endpoint. The controller at packages/server/src/api/controllers/static/index.ts:614-632 accepts the bucket parameter directly from the request body and passes it to getSignedUrl without validating against the datasource's configured bucket.
Evidence
The test suite at packages/server/src/api/routes/tests/static.spec.ts:218-235 confirms…
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-2026-72859 has been found in Budibase.
Data can be tampered with by attackers. CVSS score: 7.7/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Budibase CVE-2026-72859" on the vendor's site.
CVE-2026-72859 (Budibase) — CWE-863 / CVSS v3 7.7
Attack vector: remote (network-reachable) / no user interaction
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 Budibase.
Check the vendor advisory for the affected versions of Budibase.
Severity: High (CVSS 7.7/10). 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 request patterns matching this CVE's known IOCs. 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。 -
2Post-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。
Affected packages
References
- package github.com
- web github.com
- web nvd.nist.gov
- web disclosure@vulncheck.com
- web github.com
- web github.com