Security and privacy

Treat both inspected pages and encoded snapshots as untrusted input.

Snapshot sensitivity

A lossless snapshot may contain:

• personal data and page text;
• input and textarea values;
• account identifiers and tokens rendered into the DOM;
• URLs, origins, titles, and frame names;
• interaction state that reveals what a user was doing.

Do not export, log, or attach snapshots to model requests without an explicit data policy. Domstamp ships trusted structural redaction and Playwright pixel masks, but the caller still owns policy completeness: a value not named by the policy remains lossless.

Redaction boundary

Core redaction runs after adapter output is structurally validated and before consumer plugins. It uses literal matching rather than attacker-controlled regular expressions, preserves node and frame IDs, and revalidates the transformed graph. Runtime input values are redacted by default in redaction mode.

Pixels are a separate leak surface. When screenshot capture and redaction are both enabled, Domstamp refuses to run without at least one pixel-mask selector. Mask all regions that can render sensitive values, including canvas or cross-frame surfaces; structural redaction cannot alter already-rasterized pixels.

Hostile-page threat model

A page may attempt to:

• create extreme depth or node counts;
• mutate continuously;
• attach and detach frames;
• return very large text or attribute values;
• override browser globals;
• expose credentials available to the browser profile.

Domstamp provides node, depth, frame, byte, and time ceilings; iterative DOM traversal; cancellation; mutation diagnostics; and structural snapshot validation. These controls reduce risk but do not make a privileged browser profile safe for arbitrary websites.

TQ1 threat model

An encoded payload may contain invalid gzip, a decompression bomb, extreme nesting, oversized collections, bad string indices, duplicate keys, hostile prototype keys, or an unsupported version.

The decoder applies compressed and expanded byte ceilings plus depth, string-table, array, and object limits. Set smaller application-specific values when decoding across a trust boundary.

Deployment checklist

• Use a disposable browser context for untrusted pages.
• Do not reuse a profile containing ambient credentials.
• Run browser processes in an appropriately isolated container or sandbox.
• Capture the smallest scope and feature set required by the task.
• Keep frame, node, depth, byte, and time budgets finite.
• Treat artifacts, traces, screenshots, and TQ1 files as sensitive.
• Apply and test a complete redaction layer before data leaves its trust boundary.
• Prefer sentinel-secret tests that scan serialized snapshots and compare masked screenshots before and after the secret changes.
• Pin package and browser versions in CI.

Reporting vulnerabilities

The project must establish a private security-advisory channel before publication. Do not report vulnerabilities through a public issue once that channel exists.