CVE-2026-6620
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 · uneditedA vulnerability was found in SonicCloudOrg sonic-server up to 2.0.0. The affected element is the function Upload of the file FileTool.java of the component File Upload Endpoint. The manipulation of the argument Type results in path traversal. The attack may be launched remotely. The exploit has been made public and could be used. The vendor was contacted early about this disclosure but did not respond in any way.
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 confidencePath traversal vulnerability in the file upload functionality of sonic-server. The 'Type' parameter in the Upload function of FileTool.java lacks proper validation, allowing attackers to manipulate file paths and write files to arbitrary locations on the server via '../' sequences.
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
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
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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Identify if sonic-server is installedSearch for sonic-server files, directories, or running processes. Common locations include /opt/sonic-server, /usr/local/sonic-server, or check running Java processes for sonic-server.Affected if sonic-server software is present on the system
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Determine the installed versionCheck for version files (VERSION, version.txt) in the sonic-server installation directory, or inspect the JAR/WAR file manifest. Look at pom.xml if source code is available.Affected if The installed version falls within any known vulnerable version range or cannot be determined (treat unknown versions as potentially affected)
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Verify the file upload feature is enabledCheck the application configuration files (application.yml, application.properties, or similar) for file upload settings. Look for endpoints or routes related to /upload or FileTool functionality.Affected if File upload functionality is enabled and accessible via HTTP/HTTPS endpoints
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Confirm Upload function in FileTool.java is exposedReview the application web routes or API endpoints. Check if FileTool.java is registered as a controller or handler. Look for POST requests to upload-related endpoints.Affected if The Upload function in FileTool.java is exposed as a web service endpoint
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Check if the Type parameter accepts user inputInspect the FileTool.java source code or decompiled class. Look for the Upload function and verify if the 'Type' parameter is directly used in file path construction without validation.Affected if The 'Type' parameter in the Upload function processes user-supplied input without sanitization
The system is affected if sonic-server is installed with the file upload feature enabled and the Upload function in FileTool.java is exposed via an accessible endpoint where the Type parameter accepts unsanitized input.
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 strict input validation on the Type parameter using an allowlist approach, normalize file paths to prevent traversal sequences, and restrict upload directories to prevent writing outside intended boundaries.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-6620 — 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-2026-6620 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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