CVE-2026-6477: PostgreSQL libpq lo_* functions let server superuser overwrite client stack memory

Overview

Severity

High (CVSS 8.8)

CVSS Vector

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

Exploit Status

Not Exploited

Patch Tuesday

2026-May

Released

2026-05-16

EPSS Score

0.04% (percentile: 12.4%)

Affected Products (1)

Other

• 21340-17084

Revision History

• 2026-05-16: Information published.