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Path TraversalWeakness · CWE-22

CVE-2026-9102

CRITICAL · 9.4 CVSS v4.0 Published 2026-05-20
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
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
A path traversal vulnerability exists in the Altium Enterprise Server ComparisonService due to missing filename sanitization in the Gerber file upload APIs. A regular authenticated workspace user can supply a crafted filename in the multipart Content-Disposition header to escape the intended temporary upload directory and write arbitrary files to any location on the server filesystem. Because content-controlled files can be written to web-accessible directories, this can be escalated to remote code execution in the context of the service account. It can also be used to overwrite application binaries or configuration files, leading to service takeover or denial of service.

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

A path traversal vulnerability in Altium Enterprise Server's ComparisonService allows authenticated users to escape the temporary upload directory by supplying crafted filenames with '..' sequences in the multipart Content-Disposition header. This enables writing arbitrary files to any filesystem location, which can lead to RCE when files are placed in web-accessible directories.

MitigationImplement strict filename sanitization to reject path traversal sequences ('..', '/', '\' outside allowed directories) and restrict upload directories to non-executable locations outside the web root.

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:H/VI:H/VA:H/SC:H/SI:H/SA:H/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 Altium Enterprise Server installation
    Check for Altium Enterprise Server by reviewing installed software listings, service entries, or the presence of 'Altium' directory structures on the server. Look for services named 'Altium' or 'Enterprise Server' in Windows Services or process listings.
    Affected if Altium Enterprise Server is installed and the ComparisonService component is present
  2. Identify the ComparisonService component
    Locate the ComparisonService executable or service on the system. Check installation directories (commonly under Program Files/Altium) for the ComparisonService module. Review service configuration for 'ComparisonService' entries.
    Affected if ComparisonService is installed and running as a service on the server
  3. Verify Gerber upload endpoint accessibility
    Review web server configuration or application routing to identify if the Gerber file upload endpoint in ComparisonService is exposed and accessible. Check for routes or handlers related to 'gerber', 'upload', or 'comparison' functionality.
    Affected if The Gerber upload functionality is enabled and accessible via HTTP/HTTPS
  4. Inspect upload directory configuration
    Examine the application's configuration files or upload settings to identify the designated upload directory path. Check for any path traversal protections or filename validation settings in the upload handler configuration.
    Affected if Upload directories are configurable and the application allows specifying filenames from the Content-Disposition header without sanitization
  5. Review file system permissions on web directories
    Check write permissions on web-accessible directories (wwwroot, webroot, or application public folders). Determine if the service account has write access to directories accessible via the web server.
    Affected if The service account running ComparisonService has write permissions to web-accessible directories

The environment is affected if Altium Enterprise Server with ComparisonService is running, the Gerber upload endpoint is accessible, and the service account has write access to web-accessible directories without path traversal protection on uploaded filenames.

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 strict filename sanitization to reject path traversal sequences ('..', '/', '\' outside allowed directories) and restrict upload directories to non-executable locations outside the web root.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,680
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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-2026-9102 in production — separate from our analysis above.

No notes yet

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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