xss-methodology

xss-methodology is a skill for Claude Code, Codex from wgpsec/AboutSecurity. It costs 112 tokens per session (861 once invoked), scanned A, original, no licence file.

A methodology for testing cross-site scripting, where attacker-controlled input runs as code in another user's browser. It covers reflected, stored, and DOM-based XSS in places such as searches, comments, forms, and URL parameters.

In plain words
What is it for?
Use it to test reflected, stored, and DOM XSS, including context analysis, content-security-policy bypasses, SVG payloads, and related browser behaviors.
Why use it?
It helps determine how input is inserted into a page and whether browser protections or web filters can be bypassed. This makes it easier to build a working proof of concept.

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 to test reflected, stored, and DOM XSS, including context analysis, content-security-policy bypasses, SVG payloads, and related browser behaviors.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/wgpsec/aboutsecurity/xss-methodology
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 wgpsec/AboutSecurity --skill xss-methodology
Clone the repo
git clone --depth 1 https://github.com/wgpsec/AboutSecurity

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 xss-methodology

README.md
[![agentmods](https://agentmods.dev/badge/skills/wgpsec/aboutsecurity/xss-methodology.svg)](https://agentmods.dev/skills/wgpsec/aboutsecurity/xss-methodology)
Your own site
<a href="https://agentmods.dev/skills/wgpsec/aboutsecurity/xss-methodology"><img src="https://agentmods.dev/badge/skills/wgpsec/aboutsecurity/xss-methodology.svg" alt="Measured on agentmods" height="20"></a>
Per session 112 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 861 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00112 $0.00861
Opus 5 $0.00056 $0.00430
Sonnet 5 $0.00022 $0.00172
Haiku 4.5 $0.00011 $0.00086

Measured 4d ago against content hash b8508882e02d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

xss-methodology scanned grade A with 0 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 4d 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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/exploit/web-method/xss-methodology/SKILL.md · 63 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 4d ago First seen · 63 lines · 112 tokens per session scan A b8508882e02d

Subscribe to this mod's changes

xss-methodology is a skill published in the GitHub repository wgpsec/AboutSecurity (1,725 stars, last pushed 8d ago), with no licence file. It adds 112 tokens to every session and 861 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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