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Server-Side Request Forgery (SSRF)Weakness · CWE-918

CVE-2026-48153

HIGH · 8.5 CVSS v3.1 Published 2026-05-27
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
91/100
Remediation priority · Urgent
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Budibase is an open-source low-code platform. Prior to 3.39.0, fetchToken in the OAuth2 SDK makes a POST to a builder-supplied URL with plain node-fetch, skipping the blacklist.isBlacklisted check that every other outbound fetch path in the codebase uses. The Joi schema for the OAuth2 URL has no scheme or host restriction. This vulnerability is fixed in 3.39.0.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This is a Server-Side Request Forgery (SSRF) vulnerability in Budibase's OAuth2 SDK. The fetchToken function makes POST requests to builder-supplied OAuth2 URLs using plain node-fetch, bypassing the blacklist.isBlacklisted check that all other outbound fetch paths implement. The Joi schema validation for OAuth2 URLs lacks scheme/host restrictions, allowing attackers to supply arbitrary URLs and pivot to internal services, cloud metadata endpoints, or internal network resources.

MitigationUpgrade to Budibase version 3.39.0 or later, which implements proper URL validation and blacklist checking for the OAuth2 fetchToken function.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Locate Budibase installation and version
    Check your running Budibase instance version via the admin UI (usually at /api/global/self), Helm chart, Docker container label, or package.json in the installation directory. Common paths: /opt/budibase or check container image tags.
    Affected if Version is 3.38.x or earlier (versions prior to 3.39.0 lack the fix)
  2. Identify if OAuth2 authentication is configured
    Inspect your Budibase configuration for OAuth2 provider settings. Check environment variables (e.g., OIDC_ENABLED, OAUTH_PROVIDERS) or the internal database for stored OAuth2 configurations in the _global table.
    Affected if OAuth2 or OIDC providers are enabled and configured with user-supplied callback URLs
  3. Verify OAuth2 URL validation configuration
    Examine the Joi schema validation rules applied to OAuth2 endpoints in the Budibase source code. Look for any URL validation in the OAuth2 configuration schema that restricts schemes to https:// and blocks internal hosts.
    Affected if The OAuth2 URL validation schema allows http:// URLs or does not restrict hostnames to external domains
  4. Check if fetchToken bypasses blacklist
    Review the fetchToken function implementation in the OAuth2 SDK code. Locate where the request is made via node-fetch and verify whether blacklist.isBlacklisted() is called before the request.
    Affected if The fetchToken function makes outbound requests without passing the URL through blacklist.isBlacklisted, while other fetch paths in the same codebase do perform this check
  5. Test for SSRF via OAuth2 configuration
    If you have access to configure an OAuth2 provider, attempt to set the authorization/token URLs to an internal endpoint (e.g., http://169.254.169.254/latest/meta-data for AWS metadata). Observe if Budibase successfully makes a request to this internal address.
    Affected if Budibase successfully reaches internal/internal network URLs from the OAuth2 token fetch operation, indicating the blacklist bypass is active

Your environment is affected if you run Budibase version 3.38.x or earlier AND have OAuth2/OIDC authentication enabled, as the fetchToken function will bypass the blacklist check and allow requests to arbitrary URLs including internal services.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to Budibase version 3.39.0 or later, which implements proper URL validation and blacklist checking for the OAuth2 fetchToken function.

Recommended fix High confidence

3.39.0

  1. Identify the currently running Budibase version using the admin console or deployment configuration
  2. Stop the Budibase service or deployment
  3. Consult the Budisphere upgrade documentation for your deployment method (Docker, Kubernetes, etc.)
  4. Pull or deploy Budibase version 3.39.0
  5. Verify the upgrade was successful by checking the version in the admin console
  6. Test OAuth2 authentication flows to confirm the fix is working correctly

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-48153 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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