dbcve.org
Cross-site Scripting (XSS)Weakness · CWE-79

CVE-2026-41661

MEDIUM · 6.1 CVSS v3.1 Published 2026-05-07
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

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
Admidio is an open-source user management solution. Prior to version 5.0.9, an unauthenticated attacker can execute arbitrary JavaScript in any Admidio user's browser through a reflected XSS in system/msg_window.php. The endpoint passes user input through htmlspecialchars(), which does not encode square brackets. A subsequent call to Language::prepareTextPlaceholders() converts those brackets into HTML angle brackets, producing executable markup. This issue has been patched in version 5.0.9.

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 · high confidence

Admidio prior to 5.0.9 contains a reflected XSS in system/msg_window.php where htmlspecialchars() fails to encode square brackets, and a subsequent call to Language::prepareTextPlaceholders() converts those brackets into HTML angle brackets, allowing arbitrary JavaScript execution in any user's browser.

MitigationUpdate Admidio to version 5.0.9 or later to patch the XSS vulnerability. As a defense-in-depth measure, consider deploying a WAF rule to filter or encode square brackets in query parameters.

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

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
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/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. Verify Admidio installation exists
    Locate the Admidio web application directory on your server. Look for the main configuration file (often version.php or a similar file in the includes or adm_system directory) or check your web server document root for Admidio folders.
    Affected if Admidio is not installed on this system, so the CVE does not apply.
  2. Identify installed Admidio version
    Open the version file in the Admidio installation directory. Common paths include adm_mycal.php in the root, or a version.php in the includes folder. Alternatively, check the database settings table if you have database access, as Admidio often stores the version there.
    Affected if The installed version is prior to 5.0.9 (for example, 5.0.8, 5.0.7, or older).
  3. Confirm vulnerable file exists
    Check if the file system/msg_window.php exists in the Admidio installation directory. This file must be present for the XSS to be exploitable.
    Affected if The file system/msg_window.php exists and the version is prior to 5.0.9.
  4. Verify the application is accessible via web
    Confirm that the Admidio web application is live and reachable. Attempt to access the msg_window.php file directly through a browser or curl to confirm it responds to HTTP requests.
    Affected if The application is live and the vulnerable file is accessible, with version prior to 5.0.9.

You are affected if Admidio is installed, the installed version is prior to 5.0.9, and the system/msg_window.php file is accessible on the web server.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update Admidio to version 5.0.9 or later to patch the XSS vulnerability. As a defense-in-depth measure, consider deploying a WAF rule to filter or encode square brackets in query parameters.

Recommended fix High confidence

5.0.9

  1. Backup your existing Admidio installation and database before proceeding with any upgrade
  2. Download Admidio version 5.0.9 from the official Admidio repository or website
  3. Replace the existing Admidio files with the new version 5.0.9 files, preserving your configuration and any customizations
  4. Run any database upgrade scripts included in the 5.0.9 release if applicable
  5. Verify the installation by logging in and checking that the msg_window.php endpoint no longer reflects unsanitized input

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

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,752.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-41661 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2026-41661 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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