v0.2.0 · live
CAPFRAME
§ toolsandboxserver-filesystem

edit_file

on npm:@modelcontextprotocol/server-filesystem@2026.1.14

Severity

critical0
high2
medium1
low0
info0

3 findings on this tool

  1. highexcessive agencyf-r3-edit_file

    Tool `edit_file` name implies a side effect that is not declared

    `edit_file` looks like a side-effecting tool (its name contains a mutation verb), but its `side_effects` declaration is []. A policy synthesizer cannot produce safe rules for this tool because it cannot tell what it actually does.

    fix: Declare the tool's true side effects explicitly. If the tool is genuinely read-only, rename it to match (e.g. `email.preview` rather than `email.send`).

    OWASP LLM08NIST MEASURE-2.6ATLAS T0051CAST-01
  2. highfilesystem egressf-r9-edit_file

    Tool `edit_file` writes to or deletes from the host filesystem

    `edit_file` appears to write, create, move, or delete files on the host filesystem (Make line-based edits to a text file. Each edit replaces exact line sequences with new content. Returns a git-style diff showing the changes made. Only works within allowed directories.). An agent manipulated by an indirect-injection payload can target sensitive paths (SSH keys, shell configs, application secrets) or establish persistence via cron / systemd.

    fix: Restrict the tool to an explicit allow-list of safe directories. Validate all path parameters server-side, reject traversal sequences (`../`), and gate write / delete operations behind a capframe-bind `path starts_with /safe/dir` caveat.

    OWASP LLM08NIST MANAGE-2.2ATLAS T0051CAST-01
  3. mediumunconstrained inputf-r1-edit_file

    Tool `edit_file` accepts unconstrained string input

    The following string parameter(s) have no `maxLength` constraint: `path`. Unbounded strings let an attacker stuff arbitrary payloads through the tool, including indirect-injection content.

    fix: Add a `maxLength` to each string property, or constrain with an `enum` or `pattern`. Most legitimate tool inputs fit under a few hundred bytes.

    OWASP LLM01NIST MEASURE-2.3ATLAS T0051CAST-03

About this tool

edit_file is one of 14 tools exposed by server-filesystem. The server scored 52/100 overall against the capframe rule engine (source: sandbox). Last scanned 2026-07-20.

The findings above are emitted by the public capframe.findings.v1 schema. Disagree with one? Open an issue.