Unrestricted File UploadWeakness · CWE-434

CVE-2026-34027

MEDIUM · 5.3 CVSS v4.0 Published 2026-06-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
59/100
Remediation priority · Elevated
Remotely reachable Zero-click

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
The Wertheim SafeController Software, AssemblyVersion 6.15.8328.28014, contains insufficient server-side file type validation in the /safe/contract/uploadcustomdocuments endpoint. The application validates uploaded files based on the user-controlled HTTP Content-Type value and accepts the upload if this value contains an allowed string such as pdf, jpeg, tiff, or png. An authenticated attacker with any role or permission level can spoof the Content-Type value and upload arbitrary file content.

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

The Wertheim SafeController Software's /safe/contract/uploadcustomdocuments endpoint performs file type validation based solely on the user-supplied HTTP Content-Type header rather than inspecting actual file content. An authenticated attacker can manipulate this header to bypass validation and upload arbitrary file types to the server.

MitigationImplement server-side validation that checks actual file content (magic bytes/file signatures) and validates file extensions server-side, rejecting any upload that does not match expected file types regardless of the provided Content-Type header.

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
Low
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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. Confirm Wertheim SafeController Software is installed
    Locate the software installation directory or check for running services related to SafeController. Look for the application binary or service process.
    Affected if The software is present and running
  2. Verify the uploadcustomdocuments endpoint exists
    Check application routing/configuration files for the /safe/contract/uploadcustomdocuments endpoint path.
    Affected if The endpoint is present in the application
  3. Check if authentication is required for the endpoint
    Review access control configuration or test the endpoint with and without valid credentials.
    Affected if The endpoint accepts authenticated requests (even if auth is required, an authenticated attacker could exploit this)
  4. Inspect file upload validation logic
    Examine server-side code or configuration that handles file type validation for uploads. Look for logic that only checks the Content-Type header versus actual file content inspection.
    Affected if Validation relies solely on Content-Type header without inspecting file content/headers
  5. Test for file type bypass
    Send a crafted request with manipulated Content-Type header (e.g., image/jpeg) containing a different file type (e.g., executable) to the upload endpoint.
    Affected if The server accepts and stores files with mismatched Content-Type and actual file type

A user is affected if the Wertheim SafeController Software is running with the /safe/contract/uploadcustomdocuments endpoint that validates file types based only on the HTTP Content-Type header rather than inspecting actual file content.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement server-side validation that checks actual file content (magic bytes/file signatures) and validates file extensions server-side, rejecting any upload that does not match expected file types regardless of the provided Content-Type header.

Have this fixed 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
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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-2026-34027 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