Is it allowed beyond this sign to overtake a cyclist?

In the photo there is a narrow road through a forest; a cyclist with a backpack is riding in front of you, and on the right there is sign A-25 "falling rocks". Beyond this sign, overtaking a cyclist is allowed. The answer is: yes.

The Regulation on road signs and signals states that sign A-25 "falling rocks" warns that rocks may fall onto the road or be lying on it; like every warning sign, it requires you to exercise particular caution, but it does not prohibit anything. The Road Traffic Act prohibits overtaking a power-driven vehicle on a bend marked with warning signs, when approaching the top of a hill and at a junction - none of these cases applies here, and a cyclist is not a power-driven vehicle. So you overtake according to the general rules: you make sure that you have enough visibility and space, that no one is overtaking you, you keep a distance of at least 1 m from the bicycle, and you do not force anyone coming from the opposite direction to brake. You take the warning from the sign into account during the manoeuvre: stones on the roadway may force the cyclist to swerve suddenly to the left, so you keep a larger distance and finish the manoeuvre quickly and smoothly.

Legal basis: § 3 para. 1 and § 10 para. 7 of the Regulation on road signs and signals; Art. 24 para. 1, 2 and 7 of the Road Traffic Act (Prawo o ruchu drogowym)