CVE-2026-12074

Affected versions of the nltk package are vulnerable to Path Traversal due to unsanitized user input being used to construct a file path. The FramenetCorpusReader.frame() method (via internal frame_by_name logic) joins a caller-supplied frame name directly into an XML file path without any containment check, and because the resulting path is built as a plain string rather than a PathPointer, it is opened with the builtin open(), which bypasses the nltk.pathsec sandbox entirely, even when ENFORCE=True is set. An attacker who controls the frame name passed to frame() can insert ../ sequences to escape the intended corpus directory and read arbitrary XML files elsewhere on the filesystem, with parsed file content returned directly to the caller, resulting in Information Disclosure of sensitive files such as configuration data or on-disk credentials stored as XML.