CVE-2025-67288
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 · uneditedAn arbitrary file upload vulnerability in Umbraco CMS v16.3.3 allows attackers to execute arbitrary code by uploading a crafted PDF file. NOTE: this is disputed by the Supplier because the responsibility for file validation (as shown in the documentation) belongs to the system administrator who is implementing Umbraco CMS in their environment, not to Umbraco CMS itself. The Supplier also states that PDF JavaScript runs in a completely isolated sandbox, not the browser's DOM context, which means that privilege boundaries would not be crossed, a related issue to CVE-2023-49279.
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 confidenceUmbraco CMS v16.3.3 contains an arbitrary file upload vulnerability allowing attackers to upload crafted PDF files and execute arbitrary code. The vulnerability stems from insufficient validation of uploaded PDF files, which can contain malicious JavaScript or embedded content.
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= 16.3.3CVSS 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
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
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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Verify the installed Umbraco CMS versionCheck the version file in the application root directory (typically version.txt or examine the DLL assembly version for Umbraco.Cms.dll), or log into the Umbraco backoffice and navigate to the About section to view the exact version numberAffected if The installed version is exactly 16.3.3
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Confirm the backoffice is accessibleVerify that the Umbraco backoffice login endpoint (/umbraco) is accessible and authentication is not enforced by external web server rules that would prevent attacker accessAffected if The backoffice interface is reachable without additional network-level restrictions blocking access
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Identify PDF upload capabilityLocate the media library or any custom form that accepts file uploads in the Umbraco installation; check the ~/App_Data/TEMP/ and ~/Media/ directories for upload handlers; examine web.config or application settings for any upload-related configurationAffected if A media upload feature exists that accepts PDF file uploads without requiring authentication beyond standard backoffice login
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Check for custom file validationReview any custom IValidate implementations or MediaTypeConfiguration settings in the ~/App_Data/Umbraco/ directory that may provide additional PDF validation beyond default Umbraco behaviorAffected if No custom PDF validation or sanitization is configured beyond default Umbraco settings
A system is affected if it runs exactly version 16.3.3 and has an accessible backoffice with PDF upload capability without additional custom validation layers.
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.
From vendor dataImplement proper file validation and sanitization for uploaded files, specifically for PDF files. Configure the system to validate file MIME types, remove potentially dangerous PDF features (JavaScript, embedded objects), and consider deploying additional security controls at the web server level.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA3.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2025-67288 — 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-2025-67288 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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