Security fixes land on the latest released minor version. Older versions are not patched.

Please do not open a public issue for a security problem.

Report it through GitHub's private vulnerability reporting: open the Security tab and choose Report a vulnerability. That creates a private advisory only you and the maintainers can see, and it stays private until a fix is published.

If that is unavailable to you, contact the maintainer through their GitHub profile and ask for a private channel before sending any detail.

• The affected version, operating system, .NET target framework and Python version
• The output of PyRuntime.EffectiveConfiguration?.ToString(), which records the interpreter that was actually loaded
• What an attacker can achieve, and the smallest reproduction you have

An acknowledgement within a few days, an assessment of whether the report is something PyDotNet can fix, and credit in the advisory unless you would rather stay anonymous. This is a volunteer-maintained project, so please allow reasonable time before disclosing publicly.

PyDotNet loads CPython into the host process and calls across the boundary directly. That shapes what counts as a vulnerability here.

In scope

• Memory safety in the interop layer — reference-counting errors, use-after-free, buffer handling in the zero-copy paths
• A configuration option not doing what it says: isolation that does not isolate, a virtual environment that resolves to the wrong interpreter, sys.path entries placed contrary to the requested precedence
• Anything that lets Python code reach further into the host process than the documented API allows

Out of scope

• Vulnerabilities in CPython itself — report those to the Python Security Response Team
• Vulnerabilities in third-party Python packages such as numpy or pandas — report those to their maintainers
• Executing untrusted Python code. PyDotNet runs Python in your process with your privileges, by design. Sandboxing untrusted code is not something it attempts, and PyIsolationOptions is not a security boundary — it controls which environment the interpreter reads, not what code can do once running.