PoC Exploit Released for libssh2 Remote Code Execution Vulnerability

**PoC Released for libssh2 RCE (CVE-2026-55200)** — A proof-of-concept exploit for a critical remote code execution flaw in libssh2 (affecting versions up to 1.11.1) has been published, showing how an attacker-controlled packet_length can cause a 32-bit integer wrap, undersized heap allocations, and subsequent out-of-bounds writes; the PoC includes a C11 verifier, a malicious Python SSH server demonstrating unauthenticated exploitation via a compromised or man-in-the-middle SSH server, and a local RCE harness. Upstream developers have committed a fix that enforces a packet_length upper bound, but patched releases are not yet widely distributed; organizations are advised to inventory libssh2-linked software, apply the fix or backports, and restrict connections to untrusted SSH servers.