CVE-2026-9776
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 · uneditedATEN Unizon writeFileToHttpServletResponse Directory Traversal Information Disclosure Vulnerability. This vulnerability allows remote attackers to disclose sensitive information on affected installations of ATEN Unizon. Authentication is not required to exploit this vulnerability. The specific flaw exists within the writeFileToHttpServletResponse method. The issue results from the lack of proper validation of a user-supplied path prior to using it in file operations. An attacker can leverage this vulnerability to disclose information in the context of SYSTEM. Was ZDI-CAN-28505.
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 confidenceA directory traversal vulnerability exists in ATEN Unizon's writeFileToHttpServletResponse method due to insufficient validation of user-supplied file paths. Remote attackers can exploit this without authentication to read arbitrary files on the system, potentially exposing sensitive configuration data, credentials, or system files.
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< 2.7.264CVSS 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
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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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Confirm ATEN Unizon installationLook for the Unizon service or application on the system. Check for Unizon processes running, or look in common installation directories for the Unizon application files.Affected if ATEN Unizon software is present on the system
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Determine installed versionCheck the Unizon application for its version number. This is typically visible in the web interface, an about page, or a version file in the installation directory.Affected if The version is below 2.7.264
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Verify writeFileToHttpServletResponse is exposedIdentify if the Unizon web service is accessible and check if the file download functionality is enabled. This method is typically exposed through a web endpoint.Affected if The Unizon web interface is accessible and the file response method is available
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Check network accessibilityDetermine if the Unizon service is exposed to network access. Verify whether it binds to external interfaces or is restricted to localhost only.Affected if The Unizon service is reachable from network locations rather than only local access
A system is affected if ATEN Unizon version is below 2.7.264 and the web service with the vulnerable writeFileToHttpServletResponse method is accessible, allowing unauthenticated directory traversal attacks.
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 data2.7.264
Implement strict path validation and canonicalization in the writeFileToHttpServletResponse method to prevent traversal sequences (../). Until vendor patch is available, restrict network access to the Unizon service.
- Consultation3.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-9776 — 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-2026-9776 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
- No spam, self-promotion, credentials, or personal data