Improper Access ControlWeakness · CWE-284

CVE-2026-8758

HIGH · 7.3 CVSS v3.1 Published 2026-05-17
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 Metasoft 美特软件 MetaCRM up to 6.4.0 Beta06. This impacts an unknown function of the file /common/jsp/upload3.jsp. Executing a manipulation of the argument File can lead to unrestricted upload. The attack may be launched remotely. The exploit has been publicly disclosed and may be utilized. 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 confidence

Metasoft MetaCRM contains an unrestricted file upload vulnerability in /common/jsp/upload3.jsp. The File argument is not properly validated, allowing attackers to upload malicious files (such as web shells) to the server, potentially leading to remote code execution. The vulnerability is remotely exploitable and has been publicly disclosed.

MitigationImplement strict file upload validation including allowlist of permitted file extensions, MIME type verification, file content inspection, and storage outside the web root. Alternatively, disable the affected upload3.jsp endpoint if not needed, or deploy a WAF rule to block malicious upload requests.

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 Metasoft MetaCRM is installed
    Identify if the target application is Metasoft MetaCRM by checking application banners, headers, or consulting the software inventory for the installed system.
    Affected if The system is running Metasoft MetaCRM.
  2. Locate the vulnerable upload endpoint
    Check if the file /common/jsp/upload3.jsp exists on the web server by attempting to access it via HTTP or by enumerating the web root directory structure.
    Affected if The file upload3.jsp exists and is accessible on the server.
  3. Verify upload functionality is enabled
    Attempt a test file upload to /common/jsp/upload3.jsp using the 'File' parameter to confirm the endpoint accepts uploads. Check if the upload completes without validation errors.
    Affected if The endpoint accepts file uploads via the File parameter without rejecting them.
  4. Inspect upload directory access
    After uploading a benign test file (e.g., a text file with .txt extension), verify if the file is stored in a web-accessible location by attempting to access the uploaded file via URL.
    Affected if Uploaded files are stored within the web root and are directly accessible via HTTP.
  5. Compare installed version to any known version ranges
    If version information is available (from application banners, configuration files, or software inventory), compare it against any documented affected version ranges for MetaCRM.
    Affected if The installed MetaCRM version falls within an affected version range (if such ranges become known).

If Metasoft MetaCRM is running with /common/jsp/upload3.jsp present and the File upload parameter accepts files without validation, the environment is likely affected by this unrestricted file upload vulnerability.

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 file upload validation including allowlist of permitted file extensions, MIME type verification, file content inspection, and storage outside the web root. Alternatively, disable the affected upload3.jsp endpoint if not needed, or deploy a WAF rule to block malicious upload requests.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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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-2026-8758 in production — separate from our analysis above.

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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
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  • Version or environment caveats, and links to real fixes
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