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TI-2026-27611 Aliases CVE-2026-35482

alf.io has an Authenticated RCE via Extension Script Sandbox Escape

Priority HIGH 74CWE-863Published · Updated

Key facts

Attack vector
Network
Privileges required
High
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-863.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00282 20th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed alf.io (alfio-event): 2.0-M5-2606

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
alfio-eventalf.iobefore 2.0-M5-26062.0-M5-2606Patch availableCNA
  • alf.io Vendoralfio-event Affected before 2.0-M5-2606 Fixed in 2.0-M5-2606 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:alf:alf:*:*:*:*:*:*:*:*before 2.0-M5-2606Vulnerablealfio-event
  • cpe:2.3:a:alf:alf:*:*:*:*:*:*:*:* Versions before 2.0-M5-2606 Vulnerable ·alfio-event

Remediation

  • Fix · CNA alf.io (alfio-event) Fixed in 2.0-M5-2606

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-35482

References

Exploit 1

  • TI-2024-16863 IDOR Vulnerability: Allowing Organization Owner to view the other Organizations API KEY and USERS CVSS 3.1HIGH 8.8
  • TI-2024-30371 Bypassing promo code limitations with race conditions CVSS 3.1HIGH 7.5
  • TI-2024-16862 IDOR make user can read e-mail log sent by other events CVSS 3.1HIGH 7.2
  • TI-2023-02118 Improper Neutralization of Special Elements Used in a Template Engine in alfio-event/alf.io CVSS 3.1HIGH 7.2
  • TI-2024-30370 alf.io's preloaded data as json is not escaped correctly CVSS 3.1MEDIUM 6.5
  • TI-2024-16855 Cross-Site Scripting (XSS) via File Upload in Alf.io CVSS 3.1MEDIUM 4.8
See all 9 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences