{"items":[{"id":"NVI-00018329","kind":"vulnerability","title":"PyO3 has a missing `Sync` bound on `PyCFunction::new_closure` closures","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-chgr-c6px-7xpp"],"plain_summary":"GitHub lists this reviewed advisory for pyo3. 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-11f253735ae038fdfb03ca33d9a73fde"],"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":[],"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-11f253735ae038fdfb03ca33d9a73fde","url":"https://github.com/advisories/GHSA-chgr-c6px-7xpp","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-chgr-c6px-7xpp","publisher":"GitHub Advisory Database","observed_at":"2026-11-06T15:12:54.193Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-11f253735ae038fdfb03ca33d9a73fde"],"technology":"pyo3","known_exclusions":[],"conditions_summary":"`PyCFunction::new_closure` (and the temporary `new_closure_bound` complement in the 0.21–0.22 series) required the supplied closure to be `Send + 'static` but not `Sync`. The resulting `PyCFunction` is a Python callable that can be invoked from any Python thread, which means the closure may be called concurrently from multiple threads, and needs a `Sync` bound to prevent possible data races.\n\nThe problem exists under all Python versions but is particularly vulnerable under the newer free-threaded Python variant, which do not have serial execution imposed by the Global Interpreter Lock. Under releases protected by the GIL, the ability to \"detach\" from the Python interpreter temporarily inside the closure (e.g. by `Python::detach`) makes it possible for interleaved and/or concurrent execution of various portions of the closure.\n\nPyO3 0.29.0 added a `Sync` bound to close this thread-safety bug.","public_affected_ranges":["< 0.29.0"]}],"null_published_at":"2026-11-07T07:07:39.814Z","source_updated_at":"2026-06-12T20:09:09.000Z","source_disclosed_at":"2026-06-12T20:09:05.000Z","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":"2026-11-06T15:12:54.193Z"}],"next_cursor":null,"snapshot_revision":"42594"}