libafl SKILL.md skillB
libafl from trailofbits/skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add trailofbits/skills/libafl@git:20260826.3deb39ePins git:20260826.3deb39e in mdr.lock. Pin the fingerprint instead.
- Audit grade
- B, 16 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- trailofbits/skills
- Path
plugins/testing-handbook-skills/skills/libafl/SKILL.md- Versions recorded
- 2
- Latest version
- git:20260826.3deb39e, committed Aug 26, 2026
- First version recorded
- Jan 14, 2026
- Size
- 17,143 bytes
- Repository stars
- 8,043
- License
- CC-BY-SA-4.0
Builds custom fuzzers with LibAFL, the modular Rust fuzzing library. Covers composing observers, feedbacks, mutators, schedulers, and executors into a fuzzer for targets the standard tools do not fit. Use when writing a bespoke fuzzer or mutator, fuzzing a non-standard target or architecture, implementing a fuzzing research idea, or when libFuzzer and AFL++ lack the control you need.
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
# LibAFL
LibAFL is a modular fuzzing library that implements features from AFL-based fuzzers like AFL++. Unlike traditional fuzzers, LibAFL provides all functionality in a modular and customizable way as a Rust library. It can be used as a drop-in replacement for libFuzzer or as a library to build custom fuzzers from scratch.
## When to Use
| Fuzzer | Best For | Complexity |
|--------|----------|------------|
| libFuzzer | Quick setup, single-threaded | Low |
| AFL++ | Multi-core, general purpose | Medium |
| LibAFL | Custom fuzzers, advanced features, research | High |
**Choose LibAFL when:**
- You need custom mutation strategies or feedback mechanisms
- Standard fuzzers don't support your target architecture
- You want to implement novel fuzzing techniques
- You need fine-grained control over fuzzing components
- You're conducting fuzzing research
## Quick Start
LibAFL can be used as a drop-in replacement for libFuzzer with minimal setup:
```c++
extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
// Call your code with fuzzer-provided data
my_function(data, size);
return 0;
}
```
Build LibAFL's libFuzzer compatibility layer:
```bash
…Read the whole file at its exact version.
How to install
mdr add trailofbits/skills/libafl@sha256:2f7f261439c2d87aThe line at the top of this page pins the label git:20260826.3deb39e, 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_usha236yzhipdi75)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between Jan 14, 2026 and Aug 26, 2026, about one every 224 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260826.3deb39e latest | 2026-08-26 | 3deb39e | 17,143 B | B | view · diff |
| git:20260114.695119c | 2026-01-14 | 695119c | 16,907 B | B | view |
Audit of the latest version
- fail: No curl or wget piped into a shell (matched: curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh)
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (17143 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 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
Starting a new one? Use a template for SKILL.md on mdpantry, which passes every one of these checks and says what to change in it.
Source
trailofbits/skills · 8,043 stars · license CC-BY-SA-4.0 · pushed 2026-11-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_usha236yzhipdi75 GET https://markdownregistry.com/api/v1/resolve?ref=trailofbits/skills/libafl GET https://markdownregistry.com/api/v1/blob/2f7f261439c2d87a15ddbb8a04a387fb8c211b9f20b00baf28b1466e036fc0d5
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.
More from trailofbits/skills
Every file in trailofbits/skills