CVE-2026-33622

HIGH

A PinchTab Security Policy Bypass in /wait Allows Arbitrary JavaScript Execution

Title source: cna
STIX 2.1

Description

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.

Scores

CVSS v3 8.8
EPSS 0.0009
EPSS Percentile 25.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-284 CWE-693 CWE-94
Status published
Products (3)
pinchtab/pinchtab 0.8.3 (2 CPE variants)Go
pinchtab/pinchtab 0.8.3 - 0.8.5
pinchtab/pinchtab >= 0.8.3, <= 0.8.5
Published Mar 26, 2026
Tracked Since Mar 27, 2026