alf.io has an Authenticated RCE via Extension Script Sandbox Escape
Published Jun 2, 2026
9.1
CRITICALCVSS 3.1
EPSS 0.42%
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.
Affected products
-
- Version < 2.0-M5-2606StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Alfio-Event | Alf.io | n/a |
|
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
1 other source (GitHub) ▾
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
PoCAutomatable
NoTechnical Impact
TotalDecision
n/aAssessed Jun 3, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 3, 2026.
Score over time
Jun–Oct 2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 3, 2026 | 0.42% (0.00417) | 33.71th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.21% (0.00211) | 11.23th | v5 (v2026.06.15) |
| Jun 3, 2026 | 0.04% (0.00036) | 11.02th | v4 (v2025.03.14) |
References (1)
- https://github.com/alfio-event/alf.io/security/advisories/GHSA-3w8f-mcf6-cm7h exploitx_refsource_CONFIRMVendor Advisory
| Link | Providers | Tags |
|---|---|---|
| https://github.com/alfio-event/alf.io/security/advisories/GHSA-3w8f-mcf6-cm7h | exploitx_refsource_CONFIRMVendor Advisory |
Change history (0)
No recorded changes yet.