Buffer over-read in PostgreSQL GB18030 encoding validation allows a database input provider to achieve temporary denial of service on platforms where a 1-byte over-read can elicit process termination. This affects the database server and also libpq. Versions before PostgreSQL 17.5, 16.9, 15.13, 14.18, and 13.21 are affected.
The product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer.