NY UCC § 8-306 (2021)
2021 New York Laws UCC - Uniform Commercial Code Article 8 - Investment Securities Part 3 - Transfer of Certificated and Uncertificated Securities 8-306 - Effect of Guaranteeing Signature, Indorsement, or Instruction.

Section 8--306. Effect   of   Guaranteeing  Signature,  Indorsement,  or                   Instruction.  (a) A person who guarantees a signature of an indorser of  a  security certificate warrants that at the time of signing:       (1) the signature was genuine;       (2) the  signer  was  an appropriate person to indorse, or if the            signature is by an agent, the agent had actual  authority  to            act on behalf of the appropriate person; and       (3) the signer had legal capacity to sign.  (b) A  person  who  guarantees  a  signature  of  the originator of an instruction warrants that at the time of signing:       (1) the signature was genuine;       (2) the  signer  was  an  appropriate  person  to  originate  the            instruction,  or  if  the signature is by an agent, the agent            had actual authority to act  on  behalf  of  the  appropriate            person,  if  the  person  specified in the instruction as the            registered owner was, in fact, the registered  owner,  as  to            which  fact the signature guarantor does not make a warranty;            and       (3) the signer had legal capacity to sign.  (c) A person who specially guarantees the signature of  an  originator of  an  instruction  makes the warranties of a signature guarantor under subsection (b) and also warrants that at the  time  the  instruction  is presented to the issuer:       (1) the  person  specified  in  the instruction as the registered            owner of the uncertificated security will be  the  registered            owner; and       (2) the  transfer of the uncertificated security requested in the            instruction will be registered by the issuer  free  from  all            liens,  security  interests,  restrictions,  and claims other            than those specified in the instruction.  (d) A guarantor under subsections (a) and (b) or a  special  guarantor under  subsection (c) does not otherwise warrant the rightfulness of the transfer.  (e) A person who guarantees an indorsement of a  security  certificate makes  the  warranties of a signature guarantor under subsection (a) and also warrants the rightfulness of the transfer in all respects.  (f) A person who guarantees an instruction requesting the transfer  of an  uncertificated  security makes the warranties of a special signature guarantor under subsection (c) and also warrants the rightfulness of the transfer in all respects.  (g) An issuer may not require  a  special  guaranty  of  signature,  a guaranty  of indorsement, or a guaranty of instruction as a condition to registration of transfer.  (h) The warranties under this section are made to a person  taking  or dealing with the security in reliance on the guaranty, and the guarantor is  liable  to  the  person  for  loss resulting from their breach.   An indorser or originator of an instruction whose  signature,  indorsement, or instruction has been guaranteed is liable to a guarantor for any loss suffered by the guarantor as a result of breach of the warranties of the guarantor.