CVE-2026-31271
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 · uneditedmegagao production_ssm v1.0 contains an authorization bypass vulnerability in the user addition functionality. The insert() method in UserController.java lacks authentication checks, allowing unauthenticated attackers to create super administrator accounts by directly accessing the /user/insert endpoint. This leads to complete system compromise.
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 confidenceThe megagao production_ssm v1.0 application contains a critical authorization bypass vulnerability in UserController.java where the insert() method lacks authentication checks. Attackers can directly access the /user/insert endpoint without any credentials to create super administrator accounts, achieving full system compromise.
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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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 megagao production_ssm v1.0 is deployedInspect your running web applications or deployed artifacts to identify if the megagao production_ssm application version 1.0 is present in your environmentAffected if The megagao production_ssm v1.0 application is deployed and running
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Identify the UserController.java endpoint accessibilityLocate the UserController.java file in your codebase or decompiled application and verify whether the insert() method has any authentication annotations (such as @PreAuthorize, @Secured, or custom authentication checks) or is publicly accessibleAffected if The insert() method in UserController.java lacks authentication annotations or checks, allowing unauthenticated access to /user/insert
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Test /user/insert endpoint without credentialsSend an HTTP POST request to /user/insert with a sample user creation payload (e.g., username, password, role) using a tool like curl or Burp Suite, without providing any session cookie, token, or authentication headerAffected if The endpoint accepts the request and processes it without returning an authentication error (401/403)
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Check for unauthorized super administrator accountsQuery your user database or application user storage to identify any super administrator accounts that were not created through the legitimate admin interface or by authorized personnelAffected if Unexpected or unknown super administrator accounts exist in the system
You are affected if megagao production_ssm v1.0 is deployed and the /user/insert endpoint accepts unauthenticated requests to create administrator accounts.
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 proper authentication and role-based access control (RBAC) on the /user/insert endpoint, requiring authenticated session validation and admin-level authorization before allowing user creation. Audit and reset all existing user accounts following the fix.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-31271 — 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-2026-31271 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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- Version or environment caveats, and links to real fixes
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