hunting-server-side-template-injection SKILL.md skillA
hunting-server-side-template-injection 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/hunting-server-side-template-injection@git:20260903.6dac719Pins git:20260903.6dac719 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/hunting-server-side-template-injection/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260903.6dac719, committed Sep 3, 2026
- Size
- 9,590 bytes
- Repository stars
- 26
- License
- MIT
Hunt server-side template injection where untrusted input becomes part of a template that the engine compiles and evaluates, rather than data passed into a fixed precompiled template. Covers input concatenated into a template string, a user-chosen template name or path, and admin or content features that render user-authored templates, across engines like Jinja, Twig, Freemarker, Velocity, ERB, and Handlebars. The impact runs from expression evaluation and data disclosure up to remote code…
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
# Hunting server-side template injection: when input becomes the template, not the data Template engines are safe when untrusted input is passed as a bound variable into a fixed, precompiled template: the value can only ever be data. Server-side template injection happens when input instead becomes part of the template that the engine compiles, either concatenated into a template string, supplied as the template name or path, or authored directly by a user in a feature that renders their markup. Now the engine evaluates the attacker's template expressions. The floor is expression evaluation and data disclosure; the ceiling, on many engines, is remote code execution by walking object attributes to reach a runtime, a loader, or a process API, and by escaping whatever sandbox the engine offers. The distinction that governs everything is whether input reaches compilation or only reaches rendering as data. ## When to use - Code builds a template by concatenating or interpolating untrusted input before handing it to the engine. - A template name, path, or layout is selected from user input. …
Read the whole file at its exact version.
How to install
mdr add unboundcompute/security-agent-skills/hunting-server-side-template-injection@sha256:49be960772a50939The line at the top of this page pins the label git:20260903.6dac719, 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_uj2k75u67z22ccrd)
2 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Sep 3, 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 (9590 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_uj2k75u67z22ccrd GET https://markdownregistry.com/api/v1/resolve?ref=unboundcompute/security-agent-skills/hunting-server-side-template-injection GET https://markdownregistry.com/api/v1/blob/49be960772a5093956a267edc9a7acd928b71b80c687946f31fdef8cc98cbea3
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.