Are donated securities from an estate treated differently for tax purposes than a cash charitable gift?

Generally, yes, there can be a meaningful difference, though the exact figures involved aren't something to state generally here. Donating appreciated securities, such as publicly traded shares or mutual fund units, directly to a charity, rather than selling them and donating the cash proceeds, can qualitatively reduce the tax otherwise payable on the capital gain built into those securities, in addition to generating a donation tax credit for the value donated. Simply donating cash doesn't offer that same capital-gains-related benefit, since there's no underlying investment gain being addressed.

For an estate specifically, this can matter because a deceased's capital property is generally deemed to be disposed of at fair market value immediately before death, which can trigger capital gains on the final tax return. How an estate trustee chooses to satisfy a charitable gift, donating the actual securities the estate holds versus liquidating them and giving cash, can affect the estate's overall tax picture, subject to the specific rules in place and the estate's full circumstances.

Because the tax mechanics here are detailed and estate-specific, involve the estate's accountant and lawyer together when deciding how to fund a charitable gift, rather than assuming cash and securities are treated identically.