dompurify-mxss-bypass SKILL.md skillA
dompurify-mxss-bypass from dreadnode/capabilities is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add dreadnode/capabilities/dompurify-mxss-bypass@git:20260528.f3e4348Pins git:20260528.f3e4348 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- dreadnode/capabilities
- Path
capabilities/web-security/skills/dompurify-mxss-bypass/SKILL.md- Versions recorded
- 2
- Latest version
- git:20260528.f3e4348, committed May 28, 2026
- First version recorded
- May 4, 2026
- Size
- 3,498 bytes
- Repository stars
- 22
- License
- MIT
Crafts mutation XSS payloads, identifies namespace confusion vectors, and exploits parsing differentials in DOMPurify HTML sanitizer. Use when DOMPurify.sanitize() detected in target JS source (CDN include or npm module).
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
# DOMPurify mXSS Bypass ## Pattern - `DOMPurify.sanitize()` calls in JavaScript source - CDN includes: `cdn.jsdelivr.net/npm/dompurify` or `cdnjs.cloudflare.com/ajax/libs/dompurify` - Sanitized HTML inserted via `.innerHTML` or `.outerHTML` - Version <=3.1.2 (check JS global `DOMPurify.version`) ## Workflow 1. **Fingerprint version** — check `DOMPurify.version` in browser console or grep JS source for version string in CDN URL / bundled comment 2. **Test namespace confusion** (<=3.1.2) — inject SVG/title payload, check if alert fires 3. **If stripped, check DOM mutation** — inspect browser DevTools Elements panel for DOM structure changes after sanitization (mutation evidence without execution still confirms the vector) 4. **Test node flattening** (<=3.1.2) — generate 506+ nested div payload, append SVG/style 5. **Test DOM clobbering depth reset** (<=3.1.1) — 508+ nested forms with style payload 6. **Grep for post-sanitization sinks** — search for `.text()` / `.val()` / `.textContent` output flowing into `.innerHTML` / `.html()` / `document.write()` downstream of DOMPurify …
Read the whole file at its exact version.
How to install
mdr add dreadnode/capabilities/dompurify-mxss-bypass@sha256:0910c9b30dc21a0eThe line at the top of this page pins the label git:20260528.f3e4348, 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_rpyc3tuyxadv5di2)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between May 4, 2026 and May 28, 2026, about one every 24 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260528.f3e4348 latest | 2026-05-28 | f3e4348 | 3,498 B | A | view · diff |
| git:20260504.2a64374 | 2026-05-04 | 2a64374 | 1,560 B | A | view |
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 (3498 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
dreadnode/capabilities · 22 stars · license MIT · pushed 2026-11-02 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_rpyc3tuyxadv5di2 GET https://markdownregistry.com/api/v1/resolve?ref=dreadnode/capabilities/dompurify-mxss-bypass GET https://markdownregistry.com/api/v1/blob/0910c9b30dc21a0e0844803618917fed285e8c9495aca92ba456023e54d2e560
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.