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Echo: libssh2: security update to 1.11.1-1+e5

high Tenable Cloud Security Plugin ID 461752

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

 - libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow
 vulnerability in the ssh2_cipher_crypt() function in src/openssl.c that allows a malicious SSH server to
 crash any connecting client by negotiating AES-GCM ciphers during handshake. Attackers can exploit the
 underflow in the expression computing blocksize minus aadlen minus authentication tag length to trigger an
 out-of-bounds read and a memcpy call with a near-SIZE_MAX length argument, causing immediate process crash
 before any authentication occurs. (CVE-2026-66033)

Solution

Update the libssh2 library and its related packages to version 1.11.1-1+e5 or later.

See Also

https://advisory.echohq.com/cve/CVE-2026-66033

Plugin Details

Severity: High

ID: 461752

Version: Revision 1.1

Type: Local

Published: 10/2/2026

Updated: 10/2/2026

Risk Information

VPR

Risk Factor: Medium

Score: 5

Percentile: 93.23

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

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

CVSS Score Source: CVE-2026-66033

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS v4

Risk Factor: High

Base Score: 8.7

Threat Score: 6.6

Threat Vector: CVSS:4.0/E:U

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

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 7/25/2026

Vulnerability Publication Date: 7/24/2026

Reference Information

CVE: CVE-2026-66033