CVE-2026-54700 Details

A vulnerability in the ConnectBot SSH Client Library, affecting versions through 0.3.0, allows a malicious or compromised SSH server to cause excessive memory allocation. This issue arises because the SSH protocol parser trusts attacker-controlled byte lengths and element counts without proper validation. As a result, a small malformed packet can trigger the Kaitai Struct Java runtime to allocate large amounts of memory or repeatedly parse data, leading to an uncaught OutOfMemoryError that terminates the application. The vulnerability is present in the SSH transport protocol and can be exploited without authentication. Additionally, if SSH agent forwarding is enabled, malformed SSH-agent messages can be used to exploit the issue as well.

Users are advised to upgrade to version 0.3.1 or later, where the vulnerability has been fixed by validating length-prefixed fields and repeated-element counts against the remaining bytes in the containing stream. The updated version also includes proper error handling for malformed SSH packets and agent requests.