PT-2026-50528 · Libssh2 · Libssh2

Tristan Madani · Published 2026-06-17 · Updated 2026-06-17 · CVE-2026-55200

Positive Technologies (AI Summary)

CVSS v3.1

8.1

High

Base vector

AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions libssh2 versions prior to commit 7acf3df

Description An out-of-bounds write occurs in the ssh2 transport read() function because it fails to enforce upper bounds on the packet length field. Remote attackers can send crafted SSH packets with excessively large packet length values to corrupt heap memory, potentially leading to remote code execution.

Recommendations Update to the version containing commit 7acf3df.

Fix

RCE

Weakness Enumeration

CWE-680

Related Identifiers

CVE-2026-55200

Affected Products

Libssh2

References · 5

• https://github.com/libssh2/libssh2/commit/97acf3dfda80c91c3a8c9f2372546301d4a1a7a8 · Patch
• https://github.com/libssh2/libssh2/pull/2052 · Note
• https://twitter.com/VulmonFeeds/status/2067384098516013207 · Twitter Post
• https://twitter.com/CVEnew/status/2067350984439857536 · Twitter Post
• https://vulncheck.com/advisories/libssh2-out-of-bounds-write-via-unchecked-packet-length-in-transport-c · Note