CVE-2026-61632 PyMdown Extensions: Path traversal in the b64 extension lets <img src> read files outside base_path

PyMdown Extensions is a set of extensions for the Python-Markdown markdown project. In versions up to and including 10.21.3, the b64 extension is vulnerable to a path traversal that discloses arbitrary files: it inlines images referenced by by joining the src onto the configured basepath with...