# CVE-2026-31816: Budibase Universal Auth Bypass via Webhook Query Param Injection

> Unauthenticated attackers can bypass all authentication and authorization checks on any API endpoint by appending a specific webhook pattern to the URL query string.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Mar 2026
- **Updated:** 10 Mar 2026
- **Also known as:** GHSA-gw94-hprh-4wj8

## What is CVE-2026-31816?

CVE-2026-31816 is a critical authentication bypass vulnerability in budibase, published on 9 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Budibase is a low code platform for creating internal tools, workflows, and admin panels. In 3.31.4 and earlier, the Budibase server's authorized() middleware that protects every server-side API endpoint can be completely bypassed by appending a webhook path pattern to the query string of any request. The isWebhookEndpoint() function uses an unanchored regex that tests against ctx.request.url, which in Koa includes the full URL with query parameters. When the regex matches, the authorized() middleware immediately calls return next(), skipping all authentication, authorization, role checks, and CSRF protection. This means a completely unauthenticated, remote attacker can access any server-side API endpoint by simply appending ?/webhooks/trigger (or any webhook pattern variant) to the URL.

Weakness: CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2026-31816?

It affects 1 product.


Products: Budibase Budibase.

## How do I fix CVE-2026-31816?

No fix has been published for CVE-2026-31816 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-31816 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-31816 exists.

Public exploit code:

- CVE-2026-31816 - Budibase Reverse Shell Exploit (github_poc): https://github.com/imjdl/CVE-2026-31816-rshell
- Budibase - Authentication Bypass (nuclei): http/cves/2026/CVE-2026-31816.yaml

## Other vulnerabilities in budibase

- [CVE-2026-54350](https://insights.sbomify.com/CVE-2026-54350/): Budibase: Anonymous NoSQL operator injection via published-app query templates (critical 10.0)
- [CVE-2026-27702](https://insights.sbomify.com/CVE-2026-27702/): Budibase Vulnerable to Remote Code Execution via Unsafe eval() in View Filter Map Function (Budibase Cloud) (critical 9.9)
- [CVE-2026-54352](https://insights.sbomify.com/CVE-2026-54352/): Budibase: Arbitrary file read by workspace-builder via PWA-zip symlink upload (critical 9.6)
- [CVE-2026-31818](https://insights.sbomify.com/CVE-2026-31818/): Budibase: Server-Side Request Forgery via REST Connector with Empty Default Blacklist (critical 9.6)
- [CVE-2026-30240](https://insights.sbomify.com/CVE-2026-30240/): Budibase PWA ZIP Upload Path Traversal Allows Reading Arbitrary Server Files Including All Environment Secrets (critical 9.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-31816 and fix it if it is affected.

What it is: CVE-2026-31816 is a critical authentication bypass vulnerability in budibase, published on 9 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-31816 exists.

Affected product: budibase. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-31816/ (Markdown: https://insights.sbomify.com/CVE-2026-31816/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31816
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31816
- OSV: https://osv.dev/vulnerability/CVE-2026-31816

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31816/
Summaries are generated and may contain mistakes; the official description above is the record.