HIGHVulnerability
Verified
Global

NVD HIGH: CVE-2026-33622 — PinchTab is a standalone HTTP server that gives AI agents direct control over a ...

Thursday, March 26, 2026 at 09:17 PM UTC·Source: NIST NVD

Updated: Thursday, April 2, 2026 at 05:46 PM UTC

Executive Summary

PinchTab is a standalone HTTP server that gives AI agents direct control over a Chrome browser. PinchTab `v0.8.3` through `v0.8.5` allow arbitrary JavaScript execution through `POST /wait` and `POST /tabs/{id}/wait` when the request uses `fn` mode, even if `security.allowEvaluate` is disabled. `POST /evaluate` correctly enforces the `security.allowEvaluate` guard, which is disabled by default. How

Analysis

PinchTab is a standalone HTTP server that gives AI agents direct control over a Chrome browser. PinchTab `v0.8.3` through `v0.8.5` allow arbitrary JavaScript execution through `POST /wait` and `POST /tabs/{id}/wait` when the request uses `fn` mode, even if `security.allowEvaluate` is disabled. `POST /evaluate` correctly enforces the `security.allowEvaluate` guard, which is disabled by default. However, in the affected releases, `POST /wait` accepted a user-controlled `fn` expression, embedded it directly into executable JavaScript, and evaluated it in the browser context without checking the same policy. This is a security-policy bypass rather than a separate authentication bypass. Exploitation still requires authenticated API access, but a caller with the server token can execute arbitrary JavaScript in a tab context even when the operator explicitly disabled JavaScript evaluation. The current worktree fixes this by applying the same policy boundary to `fn` mode in `/wait` that already exists on `/evaluate`, while preserving the non-code wait modes. As of time of publication, a patched version is not yet available. CVSS Score: 8.8. Published: 2026-03-26T21:17:06.780.

Indicators of Compromise (1)

CVE (1)
CVE-2026-33622
Source Attribution

Originally published by NIST NVD on Mar 26, 2026. Verified by: NIST.

Related Threats