CVE-2026-33622: medium-severity vulnerability in pinchtab
A PinchTab Security Policy Bypass in /wait Allows Arbitrary JavaScript Execution
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.1epss 0.5%
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:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:N/SC:H/SI:N/SA:N
Affected products
pinchtab · pinchtabRelated CVEs — pinchtab
In the same product, most dangerous first.
CVE-2026-33623MEDIUMPinchTab: OS Command Injection via Profile Name in Windows Cleanup Routine Enables Arbitrary Command ExecutionEPSS 3.0%CVE-2026-30834HIGHPinchTab: SSRF with Full Response Exfiltration via Download HandlerEPSS 0.5%CVE-2026-33621MEDIUMPinchTab: Unapplied Rate Limiting Middleware Allows Unbounded Brute-Force of API TokenEPSS 0.3%CVE-2026-33081MEDIUMPinchTab has Blind SSRF via browser-side redirect bypass in /download URL validationEPSS 0.3%CVE-2026-33620MEDIUMPinchTab: API Bearer Token Exposed in URL Query Parameter via Server Logs and Intermediary SystemsEPSS 0.3%CVE-2026-33619MEDIUMPinchTab has Unauthenticated Blind SSRF in Task Scheduler via Unvalidated callbackUrlEPSS 0.3%