CVE-2026-6477

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-05-14 14:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-08-25 13:19 UTC Last updatedMost recent change to the record

Details

Published

2026-05-14 14:16 UTC

Last modified

2026-08-25 13:19 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-242

Record status

Modified

Affected

• PostgreSQL < 14.23
• PostgreSQL < 15.18
• PostgreSQL < 16.14
• PostgreSQL < 17.10
• PostgreSQL < 18.4

Attack profile CVSS 3.1 · 8.8

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High