Code Review & Testing · IN-DEPTH PROFILE

differential-review

Risk-first security review for diffs, commits, and pull requests with blast-radius analysis.

Best for

Security reviewers assessing consequential code changes

What you get

Triage changed files + Trace blast radius

Main limitation

Not intended for greenfield code or broad initial vulnerability discovery.

First risk

False assurance from incomplete context. A diff review can miss unchanged vulnerable dependencies, runtime configuration, or callers outside the available repository. State scope and do not convert review coverage into a security guarantee.

EVIDENCE FRESHNESS

Three checks, kept separate

A recent source check is not a runtime test or security audit.

Upstream sourceChecked 2026-08-20

Pinned revision · 9b281335

Open pinned commit
SkillSignal profileEditorial metadata

Updated 2026-08-20

Runtime & securityNot independently verified

Source review does not certify behavior or safety.

30-SECOND BRIEF

What it does—and when it fits

Differential Review is Trail of Bits' risk-first security review for pull requests, commits, and diffs. It adapts depth to repository size, uses history and test coverage, estimates blast radius, and escalates high-risk changes into adversarial analysis.

INSTALL BY AGENT

Choose your Agent

Paths come from official Agent docs or the universal installer behind skills.sh. Compatibility still follows this Skill's record.

Native

This Skill's current record explicitly names this Agent. Still inspect scripts, permissions, and external dependencies first.

Project scope.claude/skills/differential-review/
Personal scope~/.claude/skills/differential-review/

Use project scope for team sharing and personal scope across repositories. The installer defaults to project scope; add -g for personal scope.

Install command (project scope)npx skills add trailofbits/skills --skill differential-review --agent claude-code
Official agent docs

Claude Code discovers custom Skill folders automatically at project or personal scope.

View path evidence

TYPICAL WORKFLOW

A practical workflow

01

Triage changed files

Classify authentication, cryptography, external calls, and state changes by risk.

02

Trace blast radius

Use callers, dependencies, history, and removed safeguards to identify downstream impact.

03

Write evidence-backed findings

Connect each issue to lines, commits, tests, and concrete attack scenarios.

THE TRADEOFFS

Advantages and tradeoffs

Notable strengths

  1. Prioritizes risky behavior over diff size and cosmetic change volume.
  2. Makes coverage limits and confidence explicit in a durable report.

Limitations

  1. Not intended for greenfield code or broad initial vulnerability discovery.
  2. Large, high-risk changes can require hours of focused human review despite the workflow.

BEST FIT

Who it is for

Security reviewers assessing consequential code changes

Maintainers who need a traceable PR risk record

BEFORE YOU USE IT

Risks to review before use

High

False assurance from incomplete context

A diff review can miss unchanged vulnerable dependencies, runtime configuration, or callers outside the available repository. State scope and do not convert review coverage into a security guarantee.

SECURITY

What the permission profile means

  • Treat repository history and issue links as potentially sensitive evidence.
  • Require reproducible attack paths before escalating a speculative finding.

Not a security certification. External ratings are attributed references. SkillSignal has not independently executed or security-reviewed this Skill.

INSIDE THE PACKAGE

Indexed files

SKILL.mdUpstream package contentSource-linked
methodology.mdUpstream package contentSource-linked
adversarial.mdUpstream package contentSource-linked
reporting.mdUpstream package contentSource-linked

TAGS

diff-reviewblast-radiusappsec

Original SkillSignal editorial profile grounded in Trail of Bits commit 9b281335, checked 2026-08-20; not independently executed or security-certified.