CVE-2026-119613

AshAi sends unrecognized tool errors verbatim to MCP clients and the model, disclosing internal details

Published Nov 9, 2026 CVSS 4.0 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
Generation of Error Message Containing Sensitive Information vulnerability in ash-project ash_ai allows a caller of an AshAi tool to read internal error details, including module names and data values, by making a tool call fail.

AshAi.ToToolError gained an implementation for Ash.Error.Unknown.UnknownError that returns the error's error field as is, and AshAi.Tool.Errors.format/1 sends that text to MCP clients (tool calls and resource reads in AshAi.Mcp.Server) and to the model in AshAi.ToolLoop. Ash stores the full Exception.format/2 output of a raised exception, or inspect/1 of a bare {:error, term} return, in that field. A tool result that cannot be JSON-encoded raises a Protocol.UndefinedError whose text includes the inspected value, which can be a whole record with fields the tool never returns. None of these errors were logged. The fix logs them under an error id and returns only that id to the caller.

This issue affects ash_ai: from 1.5.0 before 1.5.1.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
Description Generation of Error Message Containing Sensitive Information vulnerability in ash-project ash_ai allows a caller of an AshAi tool to read internal error details, including module names and data values, by making a tool call fail. AshAi.ToToolError gained an implementation for Ash.Error.Unknown.UnknownError that returns the error's error field as is, and AshAi.Tool.Errors.format/1 sends that text to MCP clients (tool calls and resource reads in AshAi.Mcp.Server) and to the model in AshAi.ToolLoop. Ash stores the full Exception.format/2 output of a raised exception, or inspect/1 of a bare {:error, term} return, in that field. A tool result that cannot be JSON-encoded raises a Protocol.UndefinedError whose text includes the inspected value, which can be a whole record with fields the tool never returns. None of these errors were logged. The fix logs them under an error id and returns only that id to the caller. This issue affects ash_ai: from 1.5.0 before 1.5.1.
Title AshAi sends unrecognized tool errors verbatim to MCP clients and the model, disclosing internal details
First Time appeared Ash-project
Ash-project ash Ai
Weaknesses CWE-209
CPEs cpe:2.3:a:ash-project:ash_ai:*:*:*:*:*:*:*:*
Vendors & Products Ash-project
Ash-project ash Ai
References
Metrics cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
EEF
Published
Updated
Nov 12, 2026, 4:11 PM
Reserved
Oct 30, 2026, 11:45 PM
Status
Deferred
Published
Nov 9, 2026, 1:17 PM
Modified
Nov 12, 2026, 7:34 PM