Critical libssh2 Flaw Puts SSH Clients at Risk of Remote Code Execution

A public proof-of-concept exploit has been released for CVE-2026-55200, a critical vulnerability in libssh2 that allows a malicious SSH server to corrupt memory on a connecting client, potentially leading to code execution. The flaw affects all libssh2 versions up to 1.11.1 and carries a CVSS 4.0 score of 9.2. No user interaction or credentials are required for exploitation.