C_f Challenge Fails in Headless Mode – Works in Headed Mode Only

[softbomber]

I tried using the method

sb.activate_cdp_mode("https://....")
user_agent = sb.execute_script("return navigator.userAgent;")
sb.sleep(15)
sb.uc_gui_click_captcha()

to solve the Cloudflare challenge "Verify you are human by completing...".

I noticed that in headless mode, it doesn't work, but when using headed=True, everything works fine.
It was also observed that if you use a custom user-agent with headed=True, Cloudflare somehow detects that the browser is under automation control.

What should I do to solve this problem?

user_agent=Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36
sbase version: latest.

I also tried using the method sb.uc_gui_click_cf() with the same result

[mdmintz]

Duplicate of #3161 (comment).

UC Mode and CDP Mode don't support headless mode because those use PyAutoGUI for lots of things, and PyAutoGUI doesn't work with a headless browser. (Headless mode isn't needed on Linux because of the special virtual display included.)

To activate the special virtual display, use xvfb=True on Linux to run headed browsers in a GUI-less environment.

If you encounter a CF CAPTCHA that isn't automatically bypassed, use sb.uc_gui_click_captcha() to get through.

Even if not using PyAutoGUI during UC Mode / CDP Mode, a headless browser can still leave a detectable fingerprint.

Note that SeleniumBase already gives you an optimal user agent by default, so unless you know exactly which other agents are valid to use, you'll likely get detected when trying to change it.