bug description:
If "Attempt to block headless browsers" is enabled, the CAPTCHA always fails on Chrome browser on my iOS phone with iOS26. Sometimes check passes after clicking on captcha again few times. There is no issue with Safari on same device.
When it fails, captha error handler emits this:
code: instr_blocked
message: Instrumentation blocked (automated_browser)
affects:
to reproduce:
Enable "Attempt to block headless browsers"
On an iOS phone, open a site using the CAPTCHA using Google Chrome browser
Try to solve the CAPTCHA. It will try to solve and say "Error". in case it pass, refresh the page and try again (it will sure fail after few tries)
expected behavior:
I expect captcha to pass, as this real ios device with Chrome browser, with "Attempt to block headless browsers" option on.
screenshots:
N/A
versions and environment:
Mozilla/5.0 (iPhone; CPU iPhone OS 26_5_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/150.0.7871.113 Mobile/15E148 Safari
additional context:
After poking around with issue, it seems that it's related to core/src/instrumentation.js:197
if (!b && Object.getOwnPropertyNames(navigator).length !== 0) b = true;
Chrome for iOS (CriOS — a Chromium UI over WKWebView) exposes credentials as an own property of the navigator instance rather than on Navigator.prototype, so this check always evaluates to "automated browser" there.
criOS_test.html
bug description:
If "Attempt to block headless browsers" is enabled, the CAPTCHA always fails on Chrome browser on my iOS phone with iOS26. Sometimes check passes after clicking on captcha again few times. There is no issue with Safari on same device.
When it fails, captha error handler emits this:
code: instr_blocked
message: Instrumentation blocked (automated_browser)
affects:
to reproduce:
Enable "Attempt to block headless browsers"
On an iOS phone, open a site using the CAPTCHA using Google Chrome browser
Try to solve the CAPTCHA. It will try to solve and say "Error". in case it pass, refresh the page and try again (it will sure fail after few tries)
expected behavior:
I expect captcha to pass, as this real ios device with Chrome browser, with "Attempt to block headless browsers" option on.
screenshots:
N/A
versions and environment:
Mozilla/5.0 (iPhone; CPU iPhone OS 26_5_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/150.0.7871.113 Mobile/15E148 Safari
additional context:
After poking around with issue, it seems that it's related to core/src/instrumentation.js:197
if (!b && Object.getOwnPropertyNames(navigator).length !== 0) b = true;
Chrome for iOS (CriOS — a Chromium UI over WKWebView) exposes credentials as an own property of the navigator instance rather than on Navigator.prototype, so this check always evaluates to "automated browser" there.
criOS_test.html