CVE-2026-58050

Severity CVSS v4.0:

HIGH

Type:

CWE-190 Integer Overflow or Wraparound

Publication date:

28/06/2026

Last modified:

30/06/2026

Description

libssh2 through 1.11.1 reads an attacker-controlled 32-bit attribute count from a publickey-subsystem response and uses it in the allocation num_attrs * sizeof(libssh2_publickey_attribute) without bounds checking, so on 32-bit platforms the multiplication overflows to an undersized buffer. A malicious SSH server can then drive the attribute-parsing loop to write past the allocation, causing a heap buffer overflow in a connecting libssh2 client.

Impact

Vector 4.0

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N CVSS v4.0 Severity and Metrics:

Base Score: 8.30 HIGH
Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N

Attack Vector (AV): Network
Attack Complexity (AC): High
Attack Requirements (AT): None
Privileges Required (PR): None
User Interaction (UI): None
Confidentiality (VC): Low
Integrity (VI): Low
Availability (VA): High
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): None

Base Score 4.0

8.30

Severity 4.0

HIGH

Vector 3.x

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H CVSS v3.1 Severity and Metrics:

Base Score: 7.00 HIGH
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H

Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): Low
Integrity (I): Low
Availability (A): High