# CVE-2026-35482: alf.io has an Authenticated RCE via Extension Script Sandbox Escape

> An authenticated administrator can escape the extension script sandbox to execute arbitrary OS commands on the server.

- **Severity:** High 8.0 (`CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 Jun 2026
- **Updated:** 3 Jun 2026
- **Also known as:** GHSA-3w8f-mcf6-cm7h

## What is CVE-2026-35482?

CVE-2026-35482 is a high-severity code injection vulnerability in alfio-event alf.io, published on 2 Jun 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

alf.io is an open source ticket reservation system for conferences, trade shows, workshops, and meetups. Prior to version 2.0-M5-2606, a sandbox escape vulnerability in the alf.io extension script engine allows an authenticated administrator to execute arbitrary operating system commands on the server. The extension system is intended to execute restricted JavaScript in a sandboxed Rhino environment; however, a combination of an unguarded injected Java object (`returnClass`) and an incomplete AST blocklist allows the sandbox to be fully escaped using Java reflection without triggering any validation errors. Version 2.0-M5-2606 patches the issue.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-35482?

It affects 1 product.


Products: Alf Alf.

## How do I fix CVE-2026-35482?

No fix has been published for CVE-2026-35482 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-35482 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35482 exists.

## Other vulnerabilities in alfio-event alf.io

- [CVE-2023-2259](https://insights.sbomify.com/CVE-2023-2259/): Improper Neutralization of Special Elements Used in a Template Engine in alfio-event/alf.io (critical 9.1)
- [CVE-2024-25635](https://insights.sbomify.com/CVE-2024-25635/): IDOR Vulnerability: Allowing Organization Owner to view the other Organizations API KEY and USERS (high 8.8)
- [CVE-2023-2258](https://insights.sbomify.com/CVE-2023-2258/): Improper Neutralization of Formula Elements in a CSV File in alfio-event/alf.io (high 8.8)
- [CVE-2023-2260](https://insights.sbomify.com/CVE-2023-2260/): Authorization Bypass Through User-Controlled Key in alfio-event/alf.io (high 8.8)
- [CVE-2024-25628](https://insights.sbomify.com/CVE-2024-25628/): Insufficient Session Expiration in alf.io (high 7.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-35482 and fix it if it is affected.

What it is: CVE-2026-35482 is a high-severity code injection vulnerability in alfio-event alf.io, published on 2 Jun 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35482 exists.

Affected product: alfio-event alf.io. 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-2026-35482/ (Markdown: https://insights.sbomify.com/CVE-2026-35482/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-35482
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-35482
- OSV: https://osv.dev/vulnerability/CVE-2026-35482

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-35482/
Summaries are generated and may contain mistakes; the official description above is the record.