Additional Study Information: The purpose of this study is to find the highest dose of CBL0137 that can be given safely to patients with solid tumors that have come back (relapsed) or does not respond to treatment (refractory) solid tumors, including the CNS tumors and lymphoma. CBL0137 will be given into a vein on Day 1 and Day 8 of a 21 day cycle for up to 17 cycles, which will last about 24 months. Recruitment And Consent IRB-AAAU0568 Page 16 of 26 ( Y5M1 ) Approved for use until: 10/09/2025 Inclusion Criteria: Part A: Patients must be at least 1 year of age and 21 years of age, have been diagnosed with relapsed or refractory relapsed or refractory solid tumors or lymphoma, including patients with CNS tumors or known CNS metastases (including untreated or progressive) are eligible. Part B1: Patients must be at least 1 year of age and 21 years of age, have been diagnosed with progressive or recurrent DIPG and other H3 K27M-mutant diffuse midline gliomas previously treated with radiation therapy. Part B2: Patients must be at least 1 year of age and 31 years of age and have been diagnosed with relapsed or refractory osteosarcoma. Patients must also meet all other eligibility criteria as outlined in the study protocol.