# CVE-2026-48147: Budibase: Unanchored Regex in `matchers.ts` Allows CSRF Bypass via Query String Injection in Budibase Worker

> An unauthenticated attacker can bypass CSRF protection in Budibase Worker by injecting route patterns into the query string, allowing unauthorized state-changing actions like admin invites.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 27 May 2026
- **Updated:** 27 May 2026
- **Also known as:** GHSA-wxq7-x3qp-vcr8

## What is CVE-2026-48147?

CVE-2026-48147 is a medium-severity vulnerability in budibase, published on 27 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Budibase is an open-source low-code platform. Prior to 3.35.4, the buildMatcherRegex() / matches() functions in packages/backend-core/src/middleware/matchers.ts route patterns are compiled into unanchored regular expressions and tested against ctx.request.url, which includes the full query string. The CSRF middleware in the Budibase Worker uses this matching system to decide whether to skip CSRF token validation. An unauthenticated attacker can forge state-changing cross-origin requests against any Worker API endpoint by injecting a public route pattern into the query string, causing the CSRF middleware to skip token validation entirely. This allows actions such as sending admin invites, modifying global configuration, and managing users without a valid CSRF token. This vulnerability is fixed in 3.35.4.

Weakness: CWE-352 (Cross-Site Request Forgery), CWE-185 (Incorrect Regular Expression)

## Which versions are affected by CVE-2026-48147?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@budibase/backend-core` | npm | All versions | 3.35.4 |
| `@budibase/backend-core` | npm | All versions | 3.35.4 |

## How do I fix CVE-2026-48147?

Upgrade @budibase/backend-core to 3.35.4 or later.

## Is CVE-2026-48147 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-48147 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-48147 and fix it if it is affected.

What it is: CVE-2026-48147 is a medium-severity vulnerability in budibase, published on 27 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-48147 exists.

Affected packages and fixed versions:
- @budibase/backend-core (npm): affected all versions; fixed in 3.35.4
- @budibase/backend-core (npm): affected all versions; fixed in 3.35.4

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-2026-48147/ (Markdown: https://insights.sbomify.com/CVE-2026-48147/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-48147
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-48147
- OSV: https://osv.dev/vulnerability/CVE-2026-48147

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-48147/
Summaries are generated and may contain mistakes; the official description above is the record.