Detections
Analytics
EulerOS 2.0 SP12 : libssh2 (EulerOS-SA-2026-3279)
high Nessus Plugin ID 343735
Synopsis
The remote EulerOS host is missing multiple security updates.Description
According to the versions of the libssh2 packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :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.(CVE-2026-58050)
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)
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)
Tenable has extracted the preceding description block directly from the EulerOS libssh2 security advisory.
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.
Solution
Update the affected libssh2 packages.See Also
Plugin Details
Severity: High
ID: 343735
File Name: EulerOS_SA-2026-3279.nasl
Version: 1.1
Type: Local
Family: Huawei Local Security Checks
Published: 9/8/2026
Updated: 9/8/2026
Supported Sensors: Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 5
Percentile: 93.7
CVSS v2
Risk Factor: Medium
Base Score: 6.1
Temporal Score: 4.8
Vector: CVSS2#AV:N/AC:H/Au:N/C:P/I:N/A:C
CVSS Score Source: CVE-2025-15661
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 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:huawei:euleros:2.0, p-cpe:/a:huawei:euleros:libssh2-devel, p-cpe:/a:huawei:euleros:libssh2-help, p-cpe:/a:huawei:euleros:libssh2
Required KB Items: Host/local_checks_enabled, Host/cpu, Host/EulerOS/release, Host/EulerOS/rpm-list, Host/EulerOS/sp
Excluded KB Items: Host/EulerOS/uvp_version
Exploit Available: true
Exploit Ease: Exploits are available
Patch Publication Date: 9/8/2026
Vulnerability Publication Date: 6/17/2026
Reference Information
CVE: CVE-2025-15661, CVE-2026-55199, CVE-2026-58050, CVE-2026-58051