Report privately through GitHub's private vulnerability reporting on this repository. Please do not open a public issue for anything exploitable.

Include the extension version (from about:addons or chrome://extensions), the browser and version, and the smallest set of steps that shows the problem. Expect an acknowledgement within a week. If a fix ships, the advisory and the changelog entry will credit you unless you would rather they did not.

The published version is the supported version. Fixes go out as a new release to both stores rather than as patches to older ones.

Three credentials, all supplied by the user and all stored in browser.storage.local:

• the Tabstack API key,
• a GitHub personal access token, when the GitHub destination is in use,
• the Obsidian Local REST API key, when the Obsidian destination is in use.

All three stay in storage.local. Preferences — the filename template, the destination, the folder names — are also written to storage.sync so a second machine does not start from scratch, but the credentials are deliberately excluded: storage.sync travels through the browser account, and a token there is a token in someone else's infrastructure. src/lib/settings.test.ts asserts that the synced copy contains no secret, and syncing can be turned off per device.

The settings export is the same story: it contains preferences only, never the three credentials, because an export lands in a downloads folder that is frequently someone's cloud drive. An import ignores any credential a file tries to set. src/lib/settingsFile.test.ts asserts both.

storage.local is unencrypted, per-profile, and readable by anyone who can read the browser profile directory or run code in the extension's own context. Browsers give extensions nothing better, so treat these tokens as you would a config file on disk:

• Scope the GitHub token to a single repository with Contents: read and write, nothing else. A classic repo token grants far more than this extension needs.
• Revoke tokens when you uninstall. Uninstalling clears the profile's copy, but it does not revoke anything at the other end.

Page URLs and page content go to api.tabstack.ai for extraction, and the resulting markdown goes to the destination the user configured — nowhere else. There are no content scripts, no analytics, and no telemetry. PRIVACY.md has the details.

• No remote code. Everything shipped is in the package; nothing is fetched and evaluated at runtime.
• Filename templates cannot escape their folder. renderFilename() strips path separators from token values and drops . and .. segments from the template, so neither a page titled ../../etc/passwd nor a template of ../../{slug} writes outside the destination folder. src/lib/markdown.test.ts covers both.
• Host permissions are narrow. api.tabstack.ai and api.github.com are requested; the optional set is loopback only. The extension cannot reach arbitrary sites, and it never reads the pages you visit — extraction happens server-side, from the URL.
• Markdown is written, never executed. Extracted content is stored as a file. If you render it later, that is your renderer's business; treat saved pages as untrusted input the same way you would any downloaded file.