CVE-2025-5591
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 · uneditedKentico Xperience 13 is vulnerable to a stored cross-site scripting attack via a form component, allowing an attacker to hijack a victim user’s session and perform actions in their security context.
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 confidenceKentico Xperience 13 contains a stored cross-site scripting (XSS) vulnerability in a form component. Attackers can inject malicious scripts that persist in the application and execute when victims view the affected form, enabling session hijacking and unauthorized actions in the victim's security context.
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>= 13.0.0, < 13.0.167CVSS 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:3.1/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 checksWork through these to decide whether this CVE applies to you.
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Check Kentico Xperience versionLocate the version information in the Kentico Xperience administration interface (typically under the Help > About section) or check the CMSAssemblyInfo.cs / version.txt file in the installation directoryAffected if The installed version is 13.0.0 or higher but lower than 13.0.167
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Identify if Forms module is in useIn the Kentico Xperience admin panel, navigate to the Modules application and verify whether the 'Forms' module is enabled, or check the CMS_Module_Reference database table for Forms module entryAffected if The Forms module is enabled and forms have been created in the system
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Review existing form definitionsAccess the Forms application in the Kentico Xperience admin interface and enumerate all defined forms. Check form fields that accept user input for any unexpected or suspicious field configurationsAffected if Forms exist in the system with input-accepting fields, particularly forms that render output to users
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Inspect form data for malicious scriptsQuery the CMS_FormUserAnswers or related form data tables in the database for any stored scripts (look for <script> tags, javascript:, onload, onerror attributes, or encoded variants)Affected if Any form submissions contain potential XSS payloads in the stored data
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Check for unauthorized form modificationsReview the CMS_Form table and related form field tables for any unexpected field types or validation settings that were not authored by legitimate administratorsAffected if Form definitions have been modified without administrator action or contain unexpected field configurations
A system is affected if it runs Kentico Xperience version 13.0.0 through 13.0.166 and has the Forms module enabled with active forms, regardless of whether malicious data is yet present.
Generated from the published advisory. Verify against your own configuration.
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 · scoped13.0.167
Implement proper input validation and output encoding on the vulnerable form component to neutralize malicious script payloads. Apply context-sensitive sanitization for all user-supplied data rendered in the form's output.
13.0.167 or later
- Backup the database and all application files before proceeding with any upgrade
- Review the release notes for version 13.0.167 to understand changes and potential impacts
- Test the upgrade in a staging or development environment before applying to production
- Apply the upgrade to Xperience 13 by updating to version 13.0.167 or later
- Verify the XSS vulnerability is resolved by testing the form component that was vulnerable
- Confirm all customizations and integrations still function correctly after the upgrade
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-5591 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-5591 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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