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

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-03-26 · updated 2026-06-17
Weakness: CWE-598

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.

Affected products

pinchtab: from 0.7.8 before 0.8.4 — fixed in 0.8.4

How to fix

Upgrade to a fixed version: pinchtab 0.8.4. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-33620 or the next vulnerability affects your stack