libssh2 | Breaking Cybersecurity News | The Hacker News

A public proof-of-concept is now out for CVE-2026-55200 , a critical flaw in libssh2 that lets a malicious or compromised SSH server trigger memory corruption on a connecting client, with possible code execution. No credentials, no user interaction. The bug affects every release up to and including 1.11.1 and carries a CVSS 4.0 score of 9.2 . libssh2 is a client-side SSH library, not a server. That distinction matters. It is embedded in curl, Git, PHP, backup agents, firmware updaters, and a long tail of appliances. Anything that links it and reaches out to an untrusted SSH endpoint is a potential target. Many of those copies are statically linked, so a distro package update will not touch them, and you may not know they are there. How the bug works The flaw lives in ssh2_transport_read() in transport.c, the function that parses incoming SSH packets during the handshake. It read the attacker-controlled packet_length field and rejected only values belo...

Libssh2, a popular open source client-side C library implementing the SSHv2 protocol, has released the latest version of its software to patch a total of nine security vulnerabilities. The Libssh2 library is available for all major distributors of the Linux operating systems, including Ubuntu, Red Hat, Debian, and also comes bundled within some distributions and software as a default library. According to an  advisory published Monday, all the below listed vulnerabilities that were patched with the release of libssh2 version 1.8.1 lead to memory corruption issues which could result in arbitrary code execution on a client system in certain circumstances. Here's the list of security vulnerabilities patched in Libssh: 1. CVE-2019-3855: Possible integer overflow in transport read that could lead to an out-of-bounds write. A malicious server, or a remote attacker who compromises an SSH server, could send a specially crafted packet which could result in executing malicious ...