aflpp

aflpp is a skill for Claude Code from RedHatProductSecurity/prodsec-skills. It costs 33 tokens per session (5,183 once invoked), scanned A, original, Apache-2.0.

A multi-core fuzzing tool for C and C++ projects. Fuzzing repeatedly feeds generated or modified inputs to software to uncover crashes and other unexpected behavior.

In plain words
What is it for?
Use it to build and run fuzz tests for C or C++ code, especially when parallel execution, varied input mutations, or broader coverage is needed.
Why use it?
It helps test large or mature codebases with many inputs and can run fuzzing work across multiple CPU cores.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: positional $N argument.

Part of the prodsec-skills plugin — 133 skills shipped together

Good fit Use it to build and run fuzz tests for C or C++ code, especially when parallel execution, varied input mutations, or broader coverage is needed.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/redhatproductsecurity/prodsec-skills/aflpp
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 RedHatProductSecurity/prodsec-skills --skill aflpp
Clone the repo
git clone --depth 1 https://github.com/RedHatProductSecurity/prodsec-skills

Made for: Claude Code.

Or install prodsec-skills, the plugin that ships this one along with the rest of its 133 skills.

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 aflpp

README.md
[![agentmods](https://agentmods.dev/badge/skills/redhatproductsecurity/prodsec-skills/aflpp/github.svg)](https://agentmods.dev/skills/redhatproductsecurity/prodsec-skills/aflpp)
Your own site
<a href="https://agentmods.dev/skills/redhatproductsecurity/prodsec-skills/aflpp"><img src="https://agentmods.dev/badge/skills/redhatproductsecurity/prodsec-skills/aflpp/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for aflpp

Your own site · 80×15
<a href="https://agentmods.dev/skills/redhatproductsecurity/prodsec-skills/aflpp"><img src="https://agentmods.dev/badge/skills/redhatproductsecurity/prodsec-skills/aflpp.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 33 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,183 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 5 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Privilege Escalation · line 104
    Potential security issue detected. Manual review is recommended.
    Fix: Review the flagged content for security risks. Ensure no credentials, secrets, or sensitive data are exposed.
  • medium MCP Rug Pull · line 73
    Docker image references without a specific tag (:latest is implicit) or digest (@sha256:...) can be silently replaced by a malicious image.
    Fix: Pin the image: image:tag or image@sha256:abc123
  • medium MCP Rug Pull · line 103
    Docker image references without a specific tag (:latest is implicit) or digest (@sha256:...) can be silently replaced by a malicious image.
    Fix: Pin the image: image:tag or image@sha256:abc123
  • medium Privilege Escalation · line 120
    Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.
    Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
  • medium Privilege Escalation · line 631
    Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.
    Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
How audits are shown
Origin original 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 $0.00033 $0.05183
Opus 5 $0.00016 $0.02592
Sonnet 5 $0.00007 $0.01037
Haiku 4.5 $0.00003 $0.00518

Measured 9d ago against content hash 55fe2204c860, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

aflpp scanned grade A with 1 finding 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 9d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -O https://raw.githubusercontent.com/AFLplusplus/AFLplusplus/stable/utils/argv_fuzzing/argv-fuzz-inl.h
Origin

Copies of this mod

2 near-identical copies found in the catalogue:

  • aflpp — 86% identical, 75 lines differ
  • aflpp — 81% identical, 138 lines differ
module/skills/aflpp/SKILL.md · 633 lines

How it starts

The opening of the file, as written. The whole thing — 633 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AFL++

AFL++ is a fork of the original AFL fuzzer that offers better fuzzing performance and more advanced features while maintaining stability. A major benefit over libFuzzer is that AFL++ has stable support for running fuzzing campaigns on multiple cores, making it ideal for large-scale fuzzing efforts.

When to Use

Fuzzer Best For Complexity
AFL++ Multi-core fuzzing, diverse mutations, mature projects Medium
libFuzzer Quick setup, single-threaded, simple harnesses Low
LibAFL Custom fuzzers, research, advanced use cases High

Choose AFL++ when:

  • You need multi-core fuzzing to maximize throughput
  • Your project can be compiled with Clang or GCC
  • You want diverse mutation strategies and mature tooling
  • libFuzzer has plateaued and you need more coverage
  • You're fuzzing production codebases that benefit from parallel execution

Quick Start

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
    // Call your code with fuzzer-provided data
    check_buf((char*)data, size);
    return 0;
}

Compile and run:

# Setup AFL++ wrapper script first (see Installation)
./afl++ docker afl-clang-fast++ -DNO_MAIN=1 -O2 -fsanitize=fuzzer harness.cc main.cc -o fuzz
mkdir seeds && echo "aaaa" > seeds/minimal_seed
./afl++ docker afl-fuzz -i seeds -o out -- ./fuzz

Installation

AFL++ has many dependencies including LLVM, Python, and Rust. We recommend using a current Debian or Ubuntu distribution for fuzzing with AFL++.

Method When to Use Supported Compilers
Ubuntu/Debian repos Recent Ubuntu, basic features only Ubuntu 23.10: Clang 14 & GCC 13Debian 12: Clang 14 & GCC 12
Docker (from Docker Hub) Specific AFL++ version, Apple Silicon support As of 4.35c: Clang 19 & GCC 11
Docker (from source) Test unreleased features, apply patches Configurable in Dockerfile
From source Avoid Docker, need specific patches Adjustable via LLVM_CONFIG env var

Read the full file on GitHub · 633 lines

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. 9d ago First seen · 633 lines · 33 tokens per session scan A 55fe2204c860

Subscribe to this mod's changes

aflpp is a skill published in the GitHub repository RedHatProductSecurity/prodsec-skills (52 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 33 tokens to every session and 5,183 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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