Inherited-property modification via prototype-backed path cache

Prototype pollution in Weo.io cached-path-relative before 1.1.0 allows remote attackers to modify inherited object properties via path inputs. The cachedPathRelative function uses ordinary objects for its top-level and per-origin caches, so an origin of proto resolves through Object.prototype rather than a cache key. Reachability requires a consuming application to pass attacker-controlled origin and destination paths; the demonstrated write changes inherited data, while further impact depends on how that application uses the polluted property.