CVE-2026-63451

high

Description

The vulnerability exists due to improper buffer index progression checks inside the SSH protocol version string analyzer. Sending an unauthenticated stream containing millions of trailing null bytes before the version declaration overflows local input tracking variables.

Details

Source: Mitre, NVD

Published: 2026-07-23

Risk Information

CVSS v2

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

Severity: High

CVSS v3

Base Score: 7.5

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

Severity: High