{"items":[{"id":"NVI-00010600","kind":"vulnerability","title":"NLTK: WekaClassifier passes an unvalidated caller-controlled model path to the weka JVM, bypassing nltk.pathsec containment","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-j456-xh4h-cpf2"],"plain_summary":"GitHub lists this reviewed advisory for nltk. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-6186554432f100d354b82d92c1dd104d"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-10-27T14:50:31.000Z","value":"8.6 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-6186554432f100d354b82d92c1dd104d"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-6186554432f100d354b82d92c1dd104d","url":"https://github.com/advisories/GHSA-j456-xh4h-cpf2","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-j456-xh4h-cpf2","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T22:06:46.371Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-6186554432f100d354b82d92c1dd104d"],"technology":"nltk","known_exclusions":[],"conditions_summary":"## Summary\n`WekaClassifier` in NLTK passes a caller-controlled model file path to the weka Java VM without any `nltk.pathsec` validation. `WekaClassifier.train` puts the caller's `model_filename` verbatim into the weka argv `[\"-d\", model_filename, ...]` (weka *writes* the trained model there), and `WekaClassifier._classify_many` puts `self._model` into `[\"-l\", self._model, ...]` (weka *reads* it). Under `nltk.pathsec.ENFORCE=True` (the default on current HEAD), NLTK's stated invariant — established by advisory CVE-2026-81726 / GHSA-8mgp-746c-j5xp — is that caller-controlled model-artifact paths must be bounded to the allowed NLTK data roots before any native tool opens them. `WekaClassifier` is the one `java()`-based tool wrapper that skips this entirely, giving an untrusted workflow arbitrary-location file **write** (`-d`) and an arbitrary file **read/parse oracle** (`-l`), defeating pathsec containment.\n\nThis is a standalone, unfixed variant of the same class as CVE-2026-81726, on a code path the CVE-2026-81726 fix never touched. That advisory enumerates 6 functions (`TransitionParser.train`, `TransitionParser.parse`, `AveragedPerceptron.save`, `AveragedPerceptron.load`, `Percept","public_affected_ranges":["<= 3.10.3"]}],"null_published_at":"2026-10-31T22:27:09.625Z","source_updated_at":"2026-10-27T14:50:31.000Z","source_disclosed_at":"2026-10-27T14:50:30.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-10-31T22:06:46.371Z"}],"next_cursor":null,"snapshot_revision":"42594"}