Unauthenticated schema mutation via webhook authorization bypass
Published May 27, 2026 · Updated May 27, 2026
Missing authorization in Budibase before 3.39.0 allows remote attackers to alter webhook and automation schemas via a known webhook ID. The authorized middleware treats every /api/webhooks/schema path as public before checking ctx.user, while buildSchema converts the request body to JSON Schema and writes it to the webhook record and automation trigger outputs. Network access and valid workspace and webhook identifiers are required; successful requests corrupt builder-visible definitions and disrupt downstream bindings without exposing data.
Summary
What happened
Missing authorization in Budibase before 3.39.0 allows remote attackers to alter webhook and automation schemas via a known webhook ID. The authorized middleware treats every /api/webhooks/schema path as public before checking ctx.user, while buildSchema converts the request body to JSON Schema and writes it to the webhook record and automation trigger outputs. Network access and valid workspace and webhook identifiers are required; successful requests corrupt builder-visible definitions and disrupt downstream bindings without exposing data.
The record
- CVE
- CVE-2026-48151
- Published
- May 27, 2026
- Updated
- May 27, 2026
- Vendor
- Budibase
- Product
- Budibase
- Classifications
- CWE-862, T1565.001, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 27, 2026CVE publishedPublication date reported by the CVE source.
- May 27, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 3.39.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Official unauthenticated schema-mutation PoCproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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