Exhibit 99.1 Investor Contact: Robert Rist (617) 342-6374 CABOT CORPORATION REPORTS SECOND QUARTER FISCAL YEAR 2026 RESULTS Second Quarter 2026 Diluted earnings per share ("EPS") of $1.27 and Adjusted EPS of $1.61 BOSTON (May 5, 2026)-- Cabot Corporation (NYSE: CBT) today announced results for its second quarter fiscal year 2026. Second Quarter Highlights | (In millions, except per share amounts) | | | Three Months Ended | | | | Six Months Ended | | | --- | --- | --- | --- | --- | --- | --- | --- | --- | | ...