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GroupsessionApplication

CVE-2025-66284

MEDIUM · 5.4 CVSS v3.0 Published 2025-12-12
Fix available
A fix is available. Upgrade to 5.7.1 or later.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Stored cross-site scripting vulnerabilities exist in GroupSession Free edition prior to ver5.7.1, GroupSession byCloud prior to ver5.7.1, and GroupSession ZION prior to ver5.7.1. A logged-in user can prepare a malicious page or URL, and an arbitrary script may be executed on the web browser when another user accesses it.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Stored cross-site scripting vulnerability in GroupSession (Free, byCloud, and ZION editions) prior to version 5.7.1. An authenticated user can inject malicious JavaScript into the application, which executes when other users view the crafted content.

MitigationUpdate to GroupSession version 5.7.1 or later. Apply input validation and output encoding to user-supplied content as a defense-in-depth measure.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
GroupsessionApplication
Affected:< 5.7.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify GroupSession installation
    Locate the GroupSession application in your environment. Check for the groupsession.war file or the installation directory containing GroupSession files.
    Affected if GroupSession is deployed in your environment
  2. Determine installed GroupSession version
    Access the GroupSession admin interface or check version files in the installation directory. Look for version information typically displayed in the system settings, About page, or VERSION file within the installation.
    Affected if The installed version is any version prior to 5.7.1 (e.g., 5.7.0, 5.6.x, 5.5.x, etc.)
  3. Verify authentication is required
    Confirm that access to GroupSession requires user authentication. The vulnerability requires an authenticated user account to inject the malicious payload.
    Affected if Anonymous access is allowed AND the version is below 5.7.1, though authentication is typically required for GroupSession
  4. Confirm stored content feature exists
    Identify if users can create, edit, or submit content that is stored and displayed to other users (such as bulletin boards, forums, comments, messaging, or user profiles).
    Affected if User-generated content storage features are present and the version is below 5.7.1

You are affected if GroupSession is running and the installed version is below 5.7.1, allowing authenticated users to store content that gets displayed to other users.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 5.7.1 or later
Fixed in 5.7.1
Interim mitigation

Update to GroupSession version 5.7.1 or later. Apply input validation and output encoding to user-supplied content as a defense-in-depth measure.

Recommended fix Moderate confidence

5.7.1

  1. Identify the current GroupSession version running in your environment (Free, byCloud, or ZION)
  2. Download GroupSession version 5.7.1 or later from the official source (groupsession.jp)
  3. Review the upgrade documentation specific to your GroupSession edition
  4. Perform a backup of your current GroupSession database and configuration files
  5. Stop the GroupSession application service
  6. Install or update to version 5.7.1 following the official upgrade procedure
  7. Verify the installation was successful and the application starts correctly
  8. Confirm the XSS vulnerability is remediated by testing that user-supplied content is properly sanitized

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Groupsession Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-66284 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data