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.
Affected products
postgresql: postgresql
References10
- www.postgresql.org/support/security/CVE-2026-6477/ PatchVendor Advisory
- access.redhat.com/errata/RHSA-2026:21182
- access.redhat.com/errata/RHSA-2026:22878
- access.redhat.com/errata/RHSA-2026:26181
- access.redhat.com/errata/RHSA-2026:26203
- access.redhat.com/errata/RHSA-2026:26204
- access.redhat.com/errata/RHSA-2026:26524
- access.redhat.com/errata/RHSA-2026:26525
- access.redhat.com/errata/RHSA-2026:26561
- access.redhat.com/errata/RHSA-2026:27718
Metrics
- CVSS 3.1
-
8.8
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 40 · as of 14 November 2026
- CWE
- CWE-242CWE-120
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