SecuriTricks - CVE-2026-6477

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.

Product(s) Impacted

Vendor	Product	Versions
Postgresql	Postgresql	14.23, 15.18, 16.14, 17.10, <18.4

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-242

Use of Inherently Dangerous Function

The product calls a function that can never be guaranteed to work safely.

*CPE(s)

Affected systems and software identified for this CVE.

Type	Vendor	Product	Version	Update	Edition	Language	Software Edition	Target Software	Target Hardware	Other Information
a	postgresql	postgresql	14.23	/	/	/	/	/	/	/
a	postgresql	postgresql	15.18	/	/	/	/	/	/	/
a	postgresql	postgresql	16.14	/	/	/	/	/	/	/
a	postgresql	postgresql	17.10	/	/	/	/	/	/	/
a	postgresql	postgresql	<18.4	/	/	/	/	/	/	/

References

https://www.postgresql.org/support/security/CVE-2026-6477/

CVSS Score

8.8 / 10

CVSS Data - 3.1

Attack Vector: NETWORK
Attack Complexity: LOW
Privileges Required: NONE
Scope: UNCHANGED
Confidentiality Impact: HIGH
Integrity Impact: HIGH
Availability Impact: HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

View Vector String

Timeline

Published: May 14, 2026, 2:16 p.m.
Last Modified: May 14, 2026, 4:21 p.m.

Status : Undergoing Analysis

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

f86ef6dc-4d3a-42ad-8f28-e6d5547a5007

CVE-2026-6477