PinchTab versions 0.7.8 through 0.8.3 accepted API tokens via a query parameter named token in addition to the recommended Authorization header. When a token is passed in this way the full request URL, which contains the bearer token, can be written to logs, stored in browser history, captured by shell history, or transmitted to other systems that record entire URLs. This exposes bearer credentials to anyone who can read these logs or history entries, providing a pathway for credential theft. The weakness corresponds to CWE-598, an unsafe credential transport pattern. No direct authentication bypass occurs, but the confidentiality of the token is compromised.

The affected product is PinchTab, a standalone HTTP server that gives AI agents control over a Chrome browser. The vulnerability exists in releases from version 0.7.8 up to, but not including, version 0.8.4. Deployments that have token authentication enabled and use the query‑parameter form are impacted. PinchTab’s own security guidance recommended using the Authorization bearer header, and the vendor removed query‑string token authentication in v0.8.4.

The CVSS score of 4.3 indicates moderate impact with mainly confidentiality concerns. The EPSS score is below 1%, suggesting low probability of mass exploitation at present, and it is not listed in the CISA KEV catalog. Exploitation requires the attacker to either intercept network traffic or to gain read access to the environment where request URLs are logged or stored. Because the token is transmitted over the wire, an adversary could obtain it from logs, browser history, or shell history if they can read those files or processes. The risk is therefore limited to environments where the query‑parameter form is in use and logs are accessible to potential attackers. The vendor’s fix in v0.8.4 eliminates the possibility of this credential leakage.