CVE-2026-33620: PinchTab: API Bearer Token Exposed in URL Query Parameter via Server Logs and Intermediary Systems

Vulnerability summary

CVE-2026-33620 is a medium (CVSS 4.3) vulnerability in pinchtab. EPSS estimates a 0.28% chance of exploitation in the next 30 days, higher than 20.9% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 26-03-2026
   PublishedVulnerability first disclosed.
2. 30-03-2026
   Last modifiedVulnerability information updated.

Description

PinchTab is a standalone HTTP server that gives AI agents direct control over a Chrome browser. PinchTab `v0.7.8` through `v0.8.3` accepted the API token from a `token` URL query parameter in addition to the `Authorization` header. When a valid API credential is sent in the URL, it can be exposed through request URIs recorded by intermediaries or client-side tooling, such as reverse proxy access logs, browser history, shell history, clipboard history, and tracing systems that capture full URLs. This issue is an unsafe credential transport pattern rather than a direct authentication bypass. It only affects deployments where a token is configured and a client actually uses the query-parameter form. PinchTab's security guidance already recommended `Authorization: Bearer <token>`, but `v0.8.3` still accepted `?token=` and included first-party flows that generated and consumed URLs containing the token. This was addressed in v0.8.4 by removing query-string token authentication and requiring safer header- or session-based authentication flows.

• CWE-598Use of HTTP Request With Sensitive Query StringThe web application uses an HTTP method to process a request, but the request includes sensitive information in the query string.