CVE-2026-6477
PostgreSQL libpq lo_* functions let server superuser overwrite client stack memory
CVSS Score
8.8
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-242 |
| Vendor | n/a |
| Product | postgresql |
| Ecosystems | |
| Industries | Technology |
| Published | May 14, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
Affected Versions
n/a / PostgreSQL
18 < 18.4 17 < 17.10 16 < 16.14 15 < 15.18 0 < 14.23
References
Credits
The PostgreSQL project thanks Yu Kunpeng and Martin Heistermann for reporting this problem.