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

high Tenable Self-Hosted Container Security Plugin ID 457579

Description

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

 - libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow
 vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by
 sending a packet with a packet_length smaller than the cipher's block size during Encrypt-then-MAC cipher
 negotiation. In the fullpacket() function in src/transport.c, the ETM path allocates a buffer of
 packet_length bytes but copies blocksize minus one bytes via memcpy, causing an overflow that on 32-bit
 glibc writes attacker-controlled bytes into an adjacent chunk's SIZE field, enabling tcache bin confusion,
 overlapping live objects, and function pointer overwrite during the session handshake before
 authentication. (CVE-2026-66035)

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-2026-66035

Plugin Details

Severity: High

ID: 457579

Version: Revision 1.1

Type: Local

Published: 10/2/2026

Updated: 10/2/2026

Risk Information

VPR

Risk Factor: High

Score: 7.6

Percentile: 98.26

CVSS v2

Risk Factor: High

Base Score: 7.6

Temporal Score: 5.6

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

CVSS Score Source: CVE-2026-66035

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

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

CVSS v4

Risk Factor: High

Base Score: 7.7

Threat Score: 5.2

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/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-2026-66035

IAVA: 2026-A-0788