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.
History

Wed, 03 Jun 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Wed, 03 Jun 2026 12:45:00 +0000

Type Values Removed Values Added
First Time appeared Alfio-event
Alfio-event alf.io
Vendors & Products Alfio-event
Alfio-event alf.io

Wed, 03 Jun 2026 02:30:00 +0000

Type Values Removed Values Added
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.
Title alf.io has an Authenticated RCE via Extension Script Sandbox Escape
Weaknesses CWE-863
References
Metrics cvssV3_1

{'score': 8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-06-02T22:50:40.435Z

Updated: 2026-06-03T14:08:53.231Z

Reserved: 2026-04-02T20:49:44.454Z

Link: CVE-2026-35482

cve-icon Vulnrichment

Updated: 2026-06-03T14:08:42.265Z

cve-icon NVD

Status : Received

Published: 2026-06-02T23:16:37.473

Modified: 2026-06-03T16:16:28.630

Link: CVE-2026-35482

cve-icon Redhat

No data.