testing-llm-insecure-output-handling SKILL.md skillA
testing-llm-insecure-output-handling from unboundcompute/security-agent-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add unboundcompute/security-agent-skills/testing-llm-insecure-output-handling@git:20260816.a6124f2Pins git:20260816.a6124f2 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- unboundcompute/security-agent-skills
- Path
skills/testing-llm-insecure-output-handling/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260816.a6124f2, committed Aug 16, 2026
- Size
- 6,801 bytes
- Repository stars
- 26
- License
- MIT
Test what happens after the model speaks: whether an application trusts model output and passes it, unescaped, into a browser, a terminal, a shell, a database, or another system. Covers model-driven XSS and markup injection, data exfiltration through rendered markdown images and links, terminal and ANSI escape injection, invisible-unicode and ascii smuggling in output, and output used to build code, SQL, or shell commands. Use when reviewing any app that renders, executes, or forwards LLM…
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Testing LLM insecure output handling: the output is the other half Most LLM security attention is on the input. The output is the other half. An application that treats model output as safe and renders or executes it inherits an injection primitive, because the model can be steered (by a user or by poisoned content) into emitting exactly the payload the downstream sink will trust. The model becomes a confused deputy that writes the attacker's markup, escape sequence, or query, and the app runs it. ## When to use - The app renders model output as HTML or markdown in a browser. - The output is printed to a terminal, written to logs, or shown in a CLI agent. - Model output is concatenated into a shell command, a SQL query, a file path, or code that gets executed. - Output is forwarded to another tool, agent, or stored and later displayed. ## Scope check Test outputs and sinks you own or are authorized to test. Use benign canary payloads and observe your own instrumentation; never exfiltrate real data. If you can't name the authorization, stop. ## The loop 1. **Trace every sink model output flows into.** Follow the output from the model to …
Read the whole file at its exact version.
How to install
mdr add unboundcompute/security-agent-skills/testing-llm-insecure-output-handling@sha256:2589c2b79e9db66cThe line at the top of this page pins the label git:20260816.a6124f2, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_bew75w2rriqfviw6)
2 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Aug 16, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (6801 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
unboundcompute/security-agent-skills · 26 stars · license MIT · pushed 2026-09-08 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_bew75w2rriqfviw6 GET https://markdownregistry.com/api/v1/resolve?ref=unboundcompute/security-agent-skills/testing-llm-insecure-output-handling GET https://markdownregistry.com/api/v1/blob/2589c2b79e9db66c7c21d260217d0160f4403d23a9e9d7bfd30960c154754580
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.