Detections
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Echo: libssh2: security update to 1.11.1-1+e4

high Tenable Self-Hosted Container Security Plugin ID 463866

Description

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

 - libssh2 through 1.11.1, fixed in commit 1762685, contains a pre-authentication denial of service
 vulnerability in the SSH_MSG_EXT_INFO handler in src/packet.c that allows a malicious SSH server to cause
 a client CPU exhaustion loop by sending a crafted extension count value. A malicious server can set
 nr_extensions to 0xFFFFFFFF during key exchange, causing the client to spin in a tight CPU loop for over
 60 seconds because return values from _libssh2_get_string() are unchecked and the session timeout does not
 apply to CPU-bound loops. (CVE-2026-55199)

Solution

Update the libssh2 library and its related packages to version 1.11.1-1+e4 or later.

See Also

https://advisory.echohq.com/cve/CVE-2026-55199

Plugin Details

Severity: High

ID: 463866

Version: Revision 1.1

Type: Local

Published: 10/2/2026

Updated: 10/2/2026

Risk Information

VPR

Risk Factor: Medium

Score: 5

Percentile: 93.7

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-2026-55199

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: 8.2

Threat Score: 4.6

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/AT:P/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: 6/18/2026

Vulnerability Publication Date: 6/17/2026

Reference Information

CVE: CVE-2026-55199