# CVE-2026-41428: Budibase: Authentication Bypass via Unanchored Regex in Public Endpoint Matcher — Unauthenticated Access to Protected Endpoints

> Attackers can bypass authentication and access protected endpoints by appending public paths to query strings due to unanchored regex matching.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Apr 2026
- **Updated:** 24 Apr 2026
- **Also known as:** GHSA-8783-3wgf-jggf

## What is CVE-2026-41428?

CVE-2026-41428 is a critical authentication bypass vulnerability in budibase, published on 24 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Budibase is an open-source low-code platform. Prior to 3.35.4, the authenticated middleware uses unanchored regular expressions to match public (no-auth) endpoint patterns against ctx.request.url. Since ctx.request.url in Koa includes the query string, an attacker can access any protected endpoint by appending a public endpoint path as a query parameter. For example, POST /api/global/users/search?x=/api/system/status bypasses all authentication because the regex /api/system/status/ matches in the query string portion of the URL. This vulnerability is fixed in 3.35.4.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-41428?

2 open source packages ship an affected version, including @budibase/backend-core. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@budibase/backend-core` | npm | All versions to 3.35.3 | None |
| `@budibase/backend-core` | npm | All versions to 3.35.3 | None |

Products: Budibase Budibase.

## How do I fix CVE-2026-41428?

No fix has been published for CVE-2026-41428 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-41428 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41428 exists.

## 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-2026-41428 and fix it if it is affected.

What it is: CVE-2026-41428 is a critical authentication bypass vulnerability in budibase, published on 24 Apr 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-2026-41428 exists.

Affected packages and fixed versions:
- @budibase/backend-core (npm): affected all versions up to 3.35.3; no fix listed
- @budibase/backend-core (npm): affected all versions up to 3.35.3; no fix listed

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-2026-41428/ (Markdown: https://insights.sbomify.com/CVE-2026-41428/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-41428
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-41428
- OSV: https://osv.dev/vulnerability/CVE-2026-41428

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-41428/
Summaries are generated and may contain mistakes; the official description above is the record.