Improper Access ControlWeakness · CWE-284

CVE-2026-9421

HIGH · 7.3 CVSS v3.1 Published 2026-05-25
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
82/100
Remediation priority · High
Remotely reachable No privileges 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 vulnerability was determined in KLiK SocialMediaWebsite 1.0. This vulnerability affects the function uniqid of the file upload.inc.php of the component File Handler. This manipulation causes unrestricted upload. The attack can be initiated remotely. The exploit has been publicly disclosed and may be utilized.

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 confidence

Unrestricted file upload vulnerability in the File Handler component (upload.inc.php) of KLiK SocialMediaWebsite 1.0. The uniqid() function is being used in a way that fails to properly validate or sanitize uploaded files, allowing attackers to upload malicious files by bypassing the intended file naming/validation logic.

MitigationImplement comprehensive server-side file validation including MIME type checking, file extension allowlist, and file content analysis; store uploads outside the web root or rename files to prevent executable extensions from being served.

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
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/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 checks

Work through these to decide whether this CVE applies to you.

  1. Confirm KLiK SocialMediaWebsite installation
    Search for the application files on the web server. Look for directories containing 'KLiK' or 'SocialMediaWebsite' and locate upload.inc.php within the codebase.
    Affected if The application KLiK SocialMediaWebsite 1.0 is present on the server
  2. Verify upload.inc.php exists and is web-accessible
    Check the web root for upload.inc.php. Common paths may include /include/, /inc/, or /components/ directories. Attempt to access it via HTTP if the application is live.
    Affected if upload.inc.php exists and is accessible via the web server
  3. Inspect the file naming mechanism
    Examine the source code of upload.inc.php and related File Handler components. Search for occurrences of 'uniqid(' function calls used for generating filenames.
    Affected if The code uses uniqid() for file naming in the upload functionality
  4. Check file validation logic
    Review the File Handler component code for file type/content validation. Look for magic byte checking, MIME type validation, or content analysis routines. Check if validation occurs before file save operations.
    Affected if Insufficient or missing server-side file validation (no magic byte checking, only extension-based validation)
  5. Determine upload directory location
    Locate where uploaded files are stored. Check the upload configuration or code for the upload path. Verify if uploads are stored within the web root.
    Affected if Upload directory is within the web-accessible directory structure
  6. Verify upload functionality is enabled
    Test or review configuration to confirm the upload feature is active. Check if there are any disabled or commented-out upload-related settings in the application.
    Affected if The file upload functionality is enabled and operational

A user is affected if KLiK SocialMediaWebsite 1.0 is installed with upload.inc.php accessible and the code uses uniqid() for file naming with inadequate file validation.

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 comprehensive server-side file validation including MIME type checking, file extension allowlist, and file content analysis; store uploads outside the web root or rename files to prevent executable extensions from being served.

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-2026-9421 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
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