NewStart CGSL MAIN 7.02 : libssh2 Multiple Vulnerabilities (NS-SA-2026-0094)

high Nessus Plugin ID 343596

Synopsis

The remote NewStart CGSL host is affected by multiple vulnerabilities.

Description

The remote NewStart CGSL host, running version MAIN 7.02, has libssh2 packages installed that are affected by multiple vulnerabilities:

- A security vulnerability has been detected in libssh2 up to 1.11.1. The impacted element is the function userauth_password of the file src/userauth.c. Such manipulation of the argument username_len/password_len leads to integer overflow. The attack may be launched remotely. The name of the patch is 256d04b60d80bf1190e96b0ad1e91b2174d744b1. A patch should be applied to remediate this issue.
(CVE-2026-7598)

- libssh2 through 1.11.1, fixed in commit 2dae302, contains an out-of-bounds heap read vulnerability in the sftp_symlink() function in src/sftp.c that allows a malicious SSH server or man-in-the-middle attacker to disclose heap memory contents or cause a crash by sending a crafted SSH_FXP_NAME response. Attackers can supply a link_len value larger than the actual packet data in SSH_FXP_NAME responses for SFTP READLINK and REALPATH operations, triggering a heap buffer over-read of up to target_len minus one bytes due to the missing validation of available packet buffer size before the memcpy operation. (CVE-2025-15661)

- 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)

- libssh2 through 1.11.1 grows its publickey list with SSH2_REALLOC but does not zero-initialize new entries before parsing populates them, so a parse failure reaching the cleanup path leaves libssh2_publickey_list_free operating on an uninitialized entry. A malicious SSH server offering the publickey subsystem can use a malformed response to make cleanup free an uninitialized, attacker- influenceable attrs pointer in a connecting libssh2 client. (CVE-2026-58051)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Upgrade the vulnerable CGSL libssh2 packages. Note that updated packages may not be available yet. Please contact ZTE for more information.

Plugin Details

Severity: High

ID: 343596

File Name: newstart_cgsl_NS-SA-2026-0094_libssh2.nasl

Version: 1.1

Type: Local

Family: NewStart CGSL Local Security Checks

Published: 9/8/2026

Updated: 9/8/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.3

Percentile: 96.43

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 5.9

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

CVSS Score Source: CVE-2026-7598

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 5.9

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

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

CVSS Score Source: CVE-2025-15661

CVSS v4

Risk Factor: High

Base Score: 8.3

Threat Score: 6.9

Threat Vector: CVSS:4.0/E:P

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

CVSS Score Source: CVE-2026-58051

Vulnerability Information

CPE: cpe:/o:zte:cgsl_main:7, p-cpe:/a:zte:cgsl_main:libssh2-core, p-cpe:/a:zte:cgsl_main:libssh2-devel, p-cpe:/a:zte:cgsl_main:libssh2-docs, p-cpe:/a:zte:cgsl_main:libssh2

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/ZTE-CGSL/release, Host/ZTE-CGSL/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 9/7/2026

Vulnerability Publication Date: 5/1/2026

Reference Information

CVE: CVE-2025-15661, CVE-2026-55199, CVE-2026-58051, CVE-2026-7598

Detections

Analytics