CVE-2026-119613 AshAi sends unrecognized tool errors verbatim to MCP clients and the model, disclosing internal details
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-119613?
CVE-2026-119613 is a medium-severity vulnerability in ash-project ash_ai, published on 9 Nov 2026.
Official 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.
Weakness: CWE-209
Which versions are affected by CVE-2026-119613?
1 open source package ship an affected version, including ash_ai.
| Package | Affected | Fixed in |
|---|---|---|
ash_ai Hex | From 1.5.0 | 1.5.1 |
How do I fix CVE-2026-119613?
Upgrade ash_ai to 1.5.1 or later.
Is CVE-2026-119613 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-119613 exists.
Sources
Also known as EEF-CVE-2026-119613, GHSA-vhmw-fwrr-r6c6.