xxe

xxe is a skill for Claude Code, Codex from blacklanternsecurity/red-run. It costs 18 tokens per session (3,837 once invoked), scanned C, original, GPL-3.0.

A security-testing guide for finding and exploiting XML External Entity (XXE) injection flaws, where unsafe XML processing can expose data or trigger server requests.

In plain words
What is it for?
Use it during an approved penetration test to test XML inputs for XXE vulnerabilities.
Why use it?
It helps authorized testers examine whether an application handles untrusted XML safely.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing.

Good fit Use it during an approved penetration test to test XML inputs for XXE vulnerabilities.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/blacklanternsecurity/red-run/xxe
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add blacklanternsecurity/red-run --skill xxe
Clone the repo
git clone --depth 1 https://github.com/blacklanternsecurity/red-run

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for xxe

README.md
[![agentmods](https://agentmods.dev/badge/skills/blacklanternsecurity/red-run/xxe.svg)](https://agentmods.dev/skills/blacklanternsecurity/red-run/xxe)
Your own site
<a href="https://agentmods.dev/skills/blacklanternsecurity/red-run/xxe"><img src="https://agentmods.dev/badge/skills/blacklanternsecurity/red-run/xxe.svg" alt="Measured on agentmods" height="20"></a>
Per session 18 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,837 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 2 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00018 $0.03837
Opus 5 $0.00009 $0.01919
Sonnet 5 $0.00004 $0.00767
Haiku 4.5 $0.00002 $0.00384

Measured 5d ago against content hash 27eb963779aa, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade C, and why

xxe scanned grade C with 2 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Reaches for credential filesmediumPrivilege escalation

SSH keys, cloud credentials, git-credentials, .npmrc, /etc/shadow: reading these is how a config file becomes a credential leak.

`/home/<user>/.ssh/id_rsa`, `/var/www/html/config.php`

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

Cloud metadata endpointmediumServer-side request forgery

One request to 169.254.169.254 can return temporary IAM credentials.

<!ENTITY xxe SYSTEM "http://169.254.169.254/latest/meta-data/iam/security-credentials/">

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

skills/web/xxe/SKILL.md · 454 lines

The source is not reproduced here

Licensed GPL-3.0

The repository is licensed GPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 454 lines · 18 tokens per session scan C 27eb963779aa

Subscribe to this mod's changes

xxe is a skill published in the GitHub repository blacklanternsecurity/red-run (267 stars, last pushed 5mo ago), licensed GPL-3.0. It adds 18 tokens to every session and 3,837 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it C with 2 findings (reaches for credential files, cloud metadata endpoint). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

Related

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Perform security testing of SOAP web services by analyzing WSDL definitions and testing for XML injection, XXE, WS-Security bypass, and SOAPAction spoofing.

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Njones17/AI-agent-master-cyber-skills-list · 41 tokens

testing-for-xxe-injection-vulnerabilities

Discovering and exploiting XML External Entity injection vulnerabilities to read server files, perform SSRF, and exfiltrate data during authorized penetration tests.

Njones17/AI-agent-master-cyber-skills-list · 39 tokens

testing-for-xml-injection-vulnerabilities

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xxe-poc

Exploit XML External Entity (XXE) vulnerabilities to read local files, perform SSRF attacks, and exfiltrate data. XXE occurs when XML parsers process external entity declarations in user-supplied XML input without proper restrictions.

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