CVE-2026-116312

Inconsistent transition-capture state in PostgreSQL MERGE allows a table data modifier to make an AFTER trigger process the wrong new row, via a partitioned table MERGE that performs an INSERT before an UPDATE.  Within major versions 15-18, minor versions before PostgreSQL 18.7, 17.12, 16.16, and 15.20 are affected.  Versions before PostgreSQL 15 are unaffected.