---
id: CVE-2025-64781
title: >-
  In GroupSession Free edition prior to ver5.7.1, GroupSession byCloud prior to
  ver5.7.1, and GroupSession ZION prior to ver5.7.1, "External page display
  restriction" is set to "Do not limit" in the initial configuration
summary: >-
  In GroupSession Free edition prior to ver5.7.1, GroupSession byCloud prior to
  ver5.7.1, and GroupSession ZION prior to ver5.7.1, "External page display
  restriction" is set to "Do not limit" in the initial configuration. With this
  configu…
severity: medium
cvss: 4.7
cvssVector: 'CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N'
cwe:
  - CWE-1188
vendor: groupsession
product: groupsession
affected:
  - groupsession < 5.7.1
patched:
  - groupsession 5.7.1
published: '2025-12-12'
updated: '2026-10-01'
sourceUpdated: '2026-10-01T16:10:00.257'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-64781'
references:
  - url: 'https://groupsession.jp/info/info-news/security20251208'
    label: vultures@jpcert.or.jp
  - url: 'https://jvn.jp/en/jp/JVN19940619/'
    label: vultures@jpcert.or.jp
tags:
  - nvd
epss: 0.00207
epssPercentile: 0.09766
ingestedAt: '2026-10-01T18:55:42.304Z'
---

## Overview

In GroupSession Free edition prior to ver5.7.1, GroupSession byCloud prior to ver5.7.1, and GroupSession ZION prior to ver5.7.1, "External page display restriction" is set to "Do not limit" in the initial configuration. With this configuration, the user may be redirected to an arbitrary website when accessing a specially crafted URL.

## Affected

- `groupsession < 5.7.1`

## Remediation

Upgrade past the affected range:

- `groupsession 5.7.1`