High severity · published Oct 21, 2026
CVE-2026-114123
D365 F&O MCP Server: Official Azure one-click deployment ships with authentication disabled by default, exposing proprietary X++ source over the public internet
New
7.5
CVSS
0.4%
EPSS
No
On KEV
Description
D365 F&O MCP Server is a Model Context Protocol server for querying Dynamics 365 Finance & Operations X++ code and metadata. Prior to version 1.11.0, the officially documented Azure one-click deployment uses infrastructure/azuredeploy.json and infrastructure/main.bicep to default the apiKey parameter to an empty string and pass it to the App Service API_KEY setting. With API_KEY unset or empty, src/middleware/apiKeyAuth.ts passes requests through without authentication, while src/index.ts binds the HTTP listener to 0.0.0.0 by default. If the deployer leaves the optional key blank and does not add separate network restrictions or upstream authentication, the resulting public App Service allows unauthenticated JSON-RPC tools/call requests to /mcp. The deployment's MCP_SERVER_MODE=read-only setting does not prevent anonymous access to read/search tools, including search, get_object_info, batch_get_info, extension_info, security_info, find_references, and find_event_handlers, exposing indexed proprietary X++ source snippets and metadata. Exposed information can include business logic, extension and event-handler wiring, security-role and privilege structure, and labels originally indexed from PackagesLocalDirectory. Deployments protected by a configured API key, effective upstream authentication, or network restrictions preventing attacker access are outside this unauthenticated exposure scenario. This issue is fixed in version 1.11.0.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 36% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
D3
d365fo-mcp-server · dynamics365ninja
< 1.11.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-114123
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-114123
github.com
https://github.com/dynamics365ninja/d365fo-mcp-server/commit/384394a81e1c6c1e0149586203395240a38fc818
github.com
https://github.com/dynamics365ninja/d365fo-mcp-server/commit/e70bd051f817ebb652d664b10a944fe2c5495de2
github.com
https://github.com/dynamics365ninja/d365fo-mcp-server/releases/tag/v1.11.0
github.com
https://github.com/dynamics365ninja/d365fo-mcp-server/security/advisories/GHSA-8764-fh3m-wf7g
