When an EXECUTE or FETCH statement is executed, there are two portals:
an outer portal that is created for the EXECUTE or FETCH statement itself,
and an inner portal for the statement being executed on its behalf.
Before this commit, nothing checked that these two portals agreed on
the tuple descriptor of the rows being returned. This can be leveraged
to disclose server memory contents and achieve arbitrary code execution.
To prevent that, we can make use of an existing safety mechanism,
added by Tom Lane in commit 2f48ede080,
which allows a tuplestore DestReceiver to be informed of the tupleDesc
required by the caller, and which will cause an ERROR to occur if
that doesn't match the tupleDesc of what emerges from the executor
(modulo dropped columns, which aren't an issue in the case at hand).
Reported-by: Ben Morris in collaboration with Claude and Anthropic Research
Reported-by: Peter Geoghegan <pg@bowt.ie>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Security: CVE-2026-16239
PostgreSQL Database Management System
This directory contains the source code distribution of the PostgreSQL database management system.
PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings.
Copyright and license information can be found in the file COPYRIGHT.
General documentation about this version of PostgreSQL can be found at https://www.postgresql.org/docs/19/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/19/installation.html.
The latest version of this software, and related software, may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.