Lightstreamer Workbench observes inspected-page runtime data. Captured Lightstreamer payloads can contain proprietary or private application data. Use the private report process for a security or privacy problem.
Canonical policy URL: https://imom39a.github.io/lightstreamer-workbench-extension/security/
Supported versions
Security fixes apply to the current Chrome Web Store release and the current main branch:
| Version | Status |
|---|---|
2.0.x |
Current public release; supported |
Older releases do not get routine fixes. Install the latest Chrome Web Store version before you report a vulnerability. Do not upgrade if the vulnerability is in the upgrade process.
Report a vulnerability
Do not open a public issue with exploit details, production payloads, tokens, cookies, account identifiers, or private URLs.
- Use GitHub private vulnerability reporting.
- If the private report page is not available, open a public support issue. Ask for a maintainer security contact. Do not include vulnerability details or private data.
- Put the impact, affected version, browser version, reproduction steps, and a safe proof of concept only in the private report.
The maintainers assess exploitability, user impact, captured-data exposure, and Chrome Web Store release risk.
Use the private security path for
- Captured Evidence leaving the local browser unexpectedly.
- Tokens, cookies, credentials, private URLs, or page secrets exposed by extension behavior.
- Remote code execution, unsafe dynamic script loading, or dependency supply-chain risks.
- Extension permission expansion beyond the documented debugging need.
- Local Injection escaping its local listener or inspected-page delivery boundary.
- Captured Evidence persisting beyond the documented DevTools session boundary without clear user control.
- Chrome Web Store release credentials, private keys, or service account material.
Use public support for
- UI bugs that contain no sensitive data.
- Incorrect COMMAND state reconstruction with sanitized payloads.
- Documentation gaps or product-boundary questions.
- Feature requests.
- Fixture or local build failures.
Use the Support page to select a public report template.
Data-handling reminder
Agent access transfers requested data to a local MCP client and potentially its
model provider. Open panels automatically enable inspection and Local Injection
and connect on the default loopback port. The header status shows On, Waiting or
Off and opens Agent access and setup under More actions; the on/off control there
changes access. A new panel uses the defaults. Any local
process can use a connected panel's grant or impersonate the companion; this
mode does not isolate OS users or agents. Standalone mode still binds only
127.0.0.1, checks exact Host/path and configured extension Origin, and rejects
ordinary website origins. Those checks are not local-process authentication:
a local program can spoof an Origin. Use a trusted development host.
The retained optional authenticated protocol mutually authenticates agent clients with HMAC-SHA-256 challenges and fresh nonces. The generated 256-bit credential stays out of URLs and network messages; it lives in the agent client's configuration, never a Workbench input field. Panel connections derive a short comparison code from fresh committed ECDH keys and a connection-bound transcript. The user compares the code shown by Workbench and the agent, then approves in Workbench; the authenticated agent must confirm the same request before Evidence access in this mode. Requests expire after two minutes and cancellation discards them. The displayed code is not the private MCP credential. Local traffic is not encrypted. Possession of the MCP credential plus local access can use an approved panel's grant; this is not an individual-agent identity or a defense against a compromised browser, local administrator or local agent. The current panel does not offer authentication controls. This protocol is not part of the current setup workflow.
Native transport has been removed. All supported platforms run the same
npm-distributed Node companion over literal loopback; the extension does not
request nativeMessaging. Old native registrations are not used or modified.
Captured application text is untrusted data, never tool instructions.
Credential-name omission is defense in depth, not a guarantee that arbitrary
application fields contain no secrets. Agents cannot call arbitrary page code,
clear History or perform Server Injection through this interface.
Loss of a companion connection or a reply does not prove an Injection was not delivered. Connection retries never replay a request or resume a Scenario. Request ids deduplicate within the surviving Panel Session only; inspect the original operation and Scenario trace before further dispatch.
Workbench processes Lightstreamer Evidence in one Panel Session. The Panel Session owns one temporary Event History. A controlled Close tries to erase this History. An abnormal stop can prevent erasure. Residual data can remain until Chrome runs the extension again. A new Panel Session does not load this data. Do not attach private production events, exports, or screenshots to public issues or pull requests.