CVE-2026-50758Public exploitNetwork attack vector

Diagram data theft via unescaped session identifier

Published Jul 21, 2026 · Updated Jul 21, 2026

Reflected XSS in DayuanJiang next-ai-draw-io 0.4.13 allows remote attackers to execute JavaScript through a crafted mcp URL. The MCP HTTP server passes the mcp-derived sessionId to getHtmlPage, which inserts it into an inline JavaScript string and HTML without context-appropriate encoding. Exploitation requires a user to open the malicious URL while the local MCP server is running; the script can then read or overwrite active diagram data through wildcard-CORS API access.

CVSS severity8.1
High
EPSS probability0.72%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in DayuanJiang next-ai-draw-io 0.4.13 allows remote attackers to execute JavaScript through a crafted mcp URL. The MCP HTTP server passes the mcp-derived sessionId to getHtmlPage, which inserts it into an inline JavaScript string and HTML without context-appropriate encoding. Exploitation requires a user to open the malicious URL while the local MCP server is running; the script can then read or overwrite active diagram data through wildcard-CORS API access.

The record

CVE
CVE-2026-50758
Published
Jul 21, 2026
Updated
Jul 21, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.001Malicious Link

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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