CVE-2026-33622

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

State
Published
Severity
6.1 Medium
Published
Mar 26, 2026
Updated
Mar 27, 2026
Reserved
Mar 23, 2026

Read the record on cve.org

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

CVSSScoreVectorSource
4.06.1 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:N/SC:H/SI:N/SA:NGitHub_M

Weaknesses

  • CWE-94 Improper Control of Generation of Code ('Code Injection')
  • CWE-284 Improper Access Control
  • CWE-693 Protection Mechanism Failure

Affected Products

ProductVersions
pinchtabpinchtab
  • >= 0.8.3, <= 0.8.5Affected

References

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