Is it permissible for a Muslim woman to remove her hijab, and for a man to shave his beard, due to oppression and tyranny from ruling regimes?

Wearing the hijab (definition) is an obligatory duty by the Book, the Sunnah (definition), and scholarly consensus. It is not permissible for a woman to remove it or be negligent regarding it. However, if a woman is subjected to harm because of wearing it, it is permissible for her to avert that harm by removing a part of it, without transgression, according to the Almighty’s saying: ﴿But whoever is compelled, neither desiring it nor transgressing, there is no sin upon him.﴾ and His saying: ﴿And He has explained to you in detail what He has forbidden you, except that to which you are compelled.﴾

The harm that permits abandoning an obligation or committing a forbidden act is that which results in the destruction of life or limb, or a hardship with which life cannot properly continue. As for harm that can be endured, it does not permit abandoning an obligation.