Opportune LLP, a Houston-based business advisory firm serving the energy industry, experienced unauthorized access to data on June 22, 2026, according to a California Attorney General breach notification. Opportune LLP began notifying affected individuals on September 18, 2026, and the Vermont Attorney General received a disclosure on the same date. A breach investigation page reported that the CHAOS ransomware group claimed responsibility and said it obtained 750 GB of data; those claims have not been independently confirmed in the available sources.
The available reporting identified Social Security numbers as exposed information. The breach affected at least 56 individuals in Vermont. A California Attorney General filing identifies Opportune LLP and the June 22 access date, but the available filing content does not provide a total affected count or identify medical or financial account information. The full scope of affected individuals and data remains unclear, and further details may emerge as notifications and investigations continue.