CVE-2026-19040Public exploitNetwork attack vectorHinoki check available

Authenticated SSRF via unvalidated DCR registration endpoint

Published Aug 6, 2026 · Updated Aug 6, 2026

Server-side request forgery in Mission Squad MCP API 1.11.0 through 1.11.9 allows remote authenticated users to reach internal HTTP services. McpDcrClients.registerNewClient passes the caller-controlled OAuth DCR registrationEndpoint directly to fetch() without applying the URL checks used for transport endpoints. Access to add or resolve an external OAuth DCR-backed server is required, and the server sends the registration payload to loopback, link-local, private, or other host-reachable addresses.

CVSS severityUnavailable
Unscored
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Server-side request forgery in Mission Squad MCP API 1.11.0 through 1.11.9 allows remote authenticated users to reach internal HTTP services. McpDcrClients.registerNewClient passes the caller-controlled OAuth DCR registrationEndpoint directly to fetch() without applying the URL checks used for transport endpoints. Access to add or resolve an external OAuth DCR-backed server is required, and the server sends the registration payload to loopback, link-local, private, or other host-reachable addresses.

The record

CVE
CVE-2026-19040
Published
Aug 6, 2026
Updated
Aug 6, 2026
Vendor
Mission Squad
Product
MCP API
Classifications
CWE-918, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.11.0
  2. Affected versionversion=1.11.1
  3. Affected versionversion=1.11.2
  4. Affected versionversion=1.11.3
  5. Affected versionversion=1.11.4
  6. Affected versionversion=1.11.5
  7. Affected versionversion=1.11.6
  8. Affected versionversion=1.11.7
  9. Affected versionversion=1.11.8
  10. Affected versionversion=1.11.9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mission Squad · MCP APIversion=1.11.0; version=1.11.1; version=1.11.2; version=1.11.3; version=1.11.4; version=1.11.5; version=1.11.6; version=1.11.7; version=1.11.8; version=1.11.9

Published CVSS scores

6.3VulDBCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C
6.3VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C
6.5VulDBAV:N/AC:L/Au:S/C:P/I:P/A:P/E:POC/RL:OF/RC:C
5.3VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-918Server-Side Request Forgery
T1190Exploit Public-Facing Application

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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