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.
History

Thu, 14 May 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Thu, 14 May 2026 15:00:00 +0000

Type Values Removed Values Added
First Time appeared Postgresql
Postgresql postgresql
Vendors & Products Postgresql
Postgresql postgresql

Thu, 14 May 2026 13:30:00 +0000

Type Values Removed Values Added
Description 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.
Title PostgreSQL libpq lo_* functions let server superuser overwrite client stack memory
Weaknesses CWE-242
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: PostgreSQL

Published:

Updated: 2026-05-14T15:32:30.106Z

Reserved: 2026-04-17T00:44:19.965Z

Link: CVE-2026-6477

cve-icon Vulnrichment

Updated: 2026-05-14T15:32:25.888Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-05-14T14:16:25.347

Modified: 2026-05-14T16:21:23.190

Link: CVE-2026-6477

cve-icon Redhat

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