CVE-2026-6477

About vulnerability

Use of inherently dangerous function PQfn(…, result_is_int=0, …) in PostgreSQL libpq lo_export(), lo_read(), lo_lseek64(), and lo_tell64() functions allows the server superuser to overwrite a client stack buffer with an arbitrarily-large response. Like gets(), PQfn(…, result_is_int=0, …) stores arbitrary-length, server-determined data into a buffer of unspecified size. Because both the \lo_export command in psql and pg_dump call lo_read(), the server superuser can overwrite pg_dump or psql stack memory. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.

Affected product:

AlmaLinux 9.2 ESU , Alpine Linux 3.22 , Alpine Linux 3.23 , Amazon Linux 2 ELS , CentOS 7 ELS , Debian 10 ELS , Debian 12 , Debian 13 , Oracle Linux 7 ELS , RHEL 7 ELS , RHEL 8 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS

Affected packages:

postgresql-10 @ 10.23 (+30 more)

Use of inherently dangerous function PQfn(…, result_is_int=0, …) in PostgreSQL libpq lo_export(), lo_read(), lo_lseek64(), and lo_tell64() functions allows the server superuser to overwrite a client stack buffer with an arbitrarily-large response. Like gets(), PQfn(…, result_is_int=0, …) stores arbitrary-length, server-determined data into a buffer of unspecified size. Because both the \lo_export command in psql and pg_dump call lo_read(), the server superuser can overwrite pg_dump or psql stack memory. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.