R14.6: Strict redirect URL allowlist

Short answer: OAuth / login return URLs validated against domain allowlist. An open redirect sends your user to an attacker’s page with your login in the URL.

Group: Auth and sessions. Status: stable. Generated from the rule definitions; do not edit by hand.

Playground: https://brevio.pro/tools/agent-guard-playground?rule=R14.6

What it catches

Strict redirect URL allowlist: OAuth / login return URLs validated against domain allowlist.

Why

An open redirect sends your user to an attacker’s page with your login in the URL.

A bad example

res.redirect(req.query.next);

A good example

res.redirect(ALLOWED.has(host(next)) ? next : '/');

How it is checked

Nothing yet. No scanner and no slice card checks it: it is a standing rule for authors and reviewers.

How to silence it

A person can silence one finding with brevio-core: ignore R14.6 -- reason on the line or the line above. Without the reason it does not count. An agent cannot silence it: the agent hook and the MCP tools never honour the comment, and a pull request that adds one is reported until a reviewer allows it. Fixing the code is still the better answer.

To change what the rule flags, edit its definition in dev_rules.py or code_rules/__init__.py. That is a code change and is reviewed like one.

R14.7 Brute-force throttle
R14.8 Role-based access control
R14.1 Session token entropy
R14.2 Password hash modern algorithms
Every rule