Cross-site Scripting (XSS)Weakness · CWE-79

CVE-2026-50758

HIGH · 8.1 CVSS v3.1 Published 2026-07-21
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
88/100
Remediation priority · High
Remotely reachable No privileges 4 weeks old

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
Cross Site Scripting vulnerability in DayuanJiang next-ai-draw-io 0.4.13 allows a remote attacker to execute arbitrary code via the mcp parameter

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

Cross-Site Scripting (XSS) vulnerability in next-ai-draw-io version 0.4.13 allows remote attackers to inject arbitrary JavaScript code through the mcp parameter. The injected payload executes in victims' browsers, potentially stealing session cookies or performing actions on behalf of authenticated users.

MitigationImplement strict input validation and output encoding for the mcp parameter. Additionally, deploy Content Security Policy (CSP) headers to restrict script execution sources.

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
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/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 checks

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

  1. Identify installed version of next-ai-draw-io
    Check the package.json file, npm list output, or application banner for the exact version number of next-ai-draw-io
    Affected if Version is 0.4.13 exactly, or falls within any version range containing 0.4.13 if additional ranges are disclosed
  2. Locate the mcp parameter handler
    Search application source code for endpoint handlers that process the 'mcp' query parameter or POST body field
    Affected if Code contains a route handling the mcp parameter without visible sanitization
  3. Verify input validation exists on mcp parameter
    Inspect the code path handling the mcp parameter for input validation functions such as escaping, encoding, or whitelist filtering
    Affected if No input validation or output encoding is found for the mcp parameter before it is reflected in HTTP responses
  4. Test for XSS vulnerability in mcp parameter
    Send a benign XSS probe payload (e.g., <script>alert(1)</script>) via the mcp parameter and inspect the HTTP response for unsanitized reflection
    Affected if The payload is reflected without encoding or is executed when the response is rendered in a browser
  5. Check for compensating security controls
    Inspect HTTP response headers for Content-Security-Policy (CSP) with script-src restrictions, or verify that the application uses a modern framework with automatic XSS escaping for the relevant view
    Affected if No CSP header is present and the framework does not provide automatic contextual encoding for the mcp parameter output

The environment is affected if next-ai-draw-io version 0.4.13 is running and the mcp parameter endpoint is accessible without proper input validation or output encoding on that parameter.

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 input validation and output encoding for the mcp parameter. Additionally, deploy Content Security Policy (CSP) headers to restrict script execution sources.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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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-2026-50758 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
  • 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