# CVE-2026-46721: Broken Access Control in extension "Frontend User Registration" (sf_register)

> Attackers can assign arbitrary frontend user groups during registration or editing, gaining unauthorized access to privileged content and functionality.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 May 2026
- **Updated:** 19 May 2026
- **Also known as:** GHSA-v348-vr4q-fv9p

## What is CVE-2026-46721?

CVE-2026-46721 is a medium-severity missing authorization vulnerability in TYPO3 Extension "Frontend User Registration", published on 19 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The create and edit flows do not restrict which user properties may be submitted and do not enforce access control on the frontend user group assignment. As a result, an attacker can assign an arbitrary frontend user group to a newly registered or edited account, gaining unauthorized access to content and functionality restricted to privileged frontend user groups.

Weakness: CWE-915 (Improperly Controlled Modification of Dynamically-Determined Object Attributes), CWE-639 (Authorization Bypass Through User-Controlled Key)

## Which versions are affected by CVE-2026-46721?

4 open source packages ship an affected version, including evoweb/sf-register.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `evoweb/sf-register` | Packagist | All versions | 13.2.4 |
| `evoweb/sf-register` | Packagist | All versions | 13.2.4 |
| `evoweb/sf-register` | Packagist | From 14.0.0 | 14.0.2 |
| `evoweb/sf-register` | Packagist | From 14.0.0 | 14.0.2 |

## How do I fix CVE-2026-46721?

Upgrade evoweb/sf-register to a fixed version for your release line: 13.2.4 or 14.0.2.

## Is CVE-2026-46721 being exploited?

There is no known exploitation of CVE-2026-46721 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-46721 and fix it if it is affected.

What it is: CVE-2026-46721 is a medium-severity missing authorization vulnerability in TYPO3 Extension "Frontend User Registration", published on 19 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-46721 in the wild and no public exploit code.

Affected packages and fixed versions:
- evoweb/sf-register (Packagist): affected all versions; fixed in 13.2.4
- evoweb/sf-register (Packagist): affected all versions; fixed in 13.2.4
- evoweb/sf-register (Packagist): affected from 14.0.0; fixed in 14.0.2
- evoweb/sf-register (Packagist): affected from 14.0.0; fixed in 14.0.2

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-2026-46721/ (Markdown: https://insights.sbomify.com/CVE-2026-46721/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46721
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46721
- OSV: https://osv.dev/vulnerability/CVE-2026-46721

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46721/
Summaries are generated and may contain mistakes; the official description above is the record.