Okla. Stat. tit. 18, § 18-487
Estopped to deny liability
Any company which shall execute or guarantee any recognizance,
stipulation, bond, or undertaking under the provisions of this
article, shall be estopped in any such proceeding to deny the
liability which it shall have assumed to incur, or to deny its
corporate power to execute or guarantee any such instrument, or
assume such liability.