eresus-remediator

eresus-remediator is a skill for Claude Code, Codex from EresusSecurity/appsec-skills. It costs 84 tokens per session (1,027 once invoked), scanned A, original, Apache-2.0.

A code-security skill for fixing confirmed or likely findings from SAST, a method that checks source code for security weaknesses.

In plain words
What is it for?
Use it to patch vulnerabilities in files, functions, or endpoints, based on scan findings, review comments, attack examples, or known unsafe code paths.
Why use it?
It helps remove the underlying cause of a security bug while keeping the intended behaviour and limiting regressions.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to patch vulnerabilities in files, functions, or endpoints, based on scan findings, review comments, attack examples, or known unsafe code paths.

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Install with agentmods
npx agentmods add skills/eresussecurity/appsec-skills/eresus-remediator
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 EresusSecurity/appsec-skills --skill eresus-remediator
Clone the repo
git clone --depth 1 https://github.com/EresusSecurity/appsec-skills

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 eresus-remediator

README.md
[![agentmods](https://agentmods.dev/badge/skills/eresussecurity/appsec-skills/eresus-remediator/github.svg)](https://agentmods.dev/skills/eresussecurity/appsec-skills/eresus-remediator)
Your own site
<a href="https://agentmods.dev/skills/eresussecurity/appsec-skills/eresus-remediator"><img src="https://agentmods.dev/badge/skills/eresussecurity/appsec-skills/eresus-remediator/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 eresus-remediator

Your own site · 80×15
<a href="https://agentmods.dev/skills/eresussecurity/appsec-skills/eresus-remediator"><img src="https://agentmods.dev/badge/skills/eresussecurity/appsec-skills/eresus-remediator.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 84 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,027 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.
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 $0.00084 $0.01027
Opus 5 $0.00042 $0.00513
Sonnet 5 $0.00017 $0.00205
Haiku 4.5 $0.00008 $0.00103

Measured 10d ago against content hash e9ee01b95775, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

eresus-remediator 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 10d 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/eresus-remediator/SKILL.md · 141 lines

How it starts

The opening of the file, as written. The whole thing — 141 lines — stays where its author put it; the contents beside it link to each section on GitHub.

SAST Remediation

Purpose

Turn confirmed or likely security findings into safe, minimal, production-ready code changes. Prefer root-cause fixes over cosmetic mitigations, preserve legitimate behavior, and reduce the chance of regressions or bypasses.

Inputs

This skill works best when at least one of the following is available:

  • a finding from eresus-sast-scanner
  • a security review comment or PR thread
  • a vulnerable file/function/endpoint
  • a proof-of-concept payload or attack path

If eresus-sast-scanner is installed, load the matching vulnerability knowledge file(s) from its references/ directory before patching.


Workflow

Step 1: Reconstruct the Vulnerability Path

Before editing code, confirm:

  • the attacker-controlled source
  • the transformation path
  • the vulnerable sink
  • the intended business behavior that must still work after the fix

Do not patch from the label alone. Patch the actual code path.

Step 2: Choose the Right Fix Layer

Prefer the highest-leverage fix that closes the whole class of issue:

Problem Type Preferred Fix
SQL / NoSQL injection Parameterization, safe query builders, strict allowlists
XSS Context-specific output encoding or safe templating APIs
SSRF Destination allowlists, URL parser validation, egress restrictions
Path traversal Canonicalization plus base-directory enforcement
Auth / IDOR Server-side authorization at object/action boundary
CSRF Framework-native CSRF defense, same-site cookies, token checks
File upload Type/content validation, non-webroot storage, random filenames
Serialization / deserialization Explicit DTOs, allowlisted types, safe parser settings, integrity checks
Weak crypto Modern primitives, strong secrets, secure randomness
Race conditions Atomic operations, locking, compare-and-set, transaction boundaries

Fix at the sink when possible, but move the fix earlier if many sinks share the same unsafe input path.

Read the full file on GitHub · 141 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. 10d ago First seen · 141 lines · 84 tokens per session scan A e9ee01b95775

Subscribe to this mod's changes

eresus-remediator is a skill published in the GitHub repository EresusSecurity/appsec-skills (7 stars, last pushed 5mo ago), licensed Apache-2.0. It adds 84 tokens to every session and 1,027 once invoked, about $0.0004 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 2026-08-31.