CVE-2025-65106

This vulnerability marked as an Important vulnerability rather than a Moderate flaw because the template injection pathway enables attackers to reach and traverse Python object internals, including attributes like class, dict, and potentially globals, when untrusted template structures are evaluated. This goes far beyond simple variable misuse: once an attacker can access internal object graphs, they may extract highly sensitive data such as environment variables, configuration objects, authentication tokens, or internal state held within LangChain message objects. The attack requires no privileges, no user interaction, and succeeds over a network whenever applications accept user-provided prompt templates—meaning the impact is systemic and not isolated to a single component. Although method execution is blocked, attribute traversal combined with indexing ([]) is still sufficient to expose confidential server-side data, creating a high confidentiality impact. Because the flaw allows reading sensitive runtime state rather than just causing template mis-renders or limited information exposure, the risk crosses the threshold from Moderate to Important.