{"id":"RUSTSEC-2026-0253","summary":"Potential use-after-free due to lack of panic safety in `LruCache::pop()`","details":"`LruCache::pop()` in `lru` was not panic-safe. If the `Drop` implementation of a stored key panics during `pop()`, `self.detach()` is never called, leaving dangling pointers in the internal doubly-linked list.\n\nA subsequent cache operation that triggers eviction can then dereference these dangling pointers:\n- The node is freed from the map, but remains linked in the LRU list due to the skipped `detach()` call\n- When a new insertion causes eviction, the LRU traversal encounters the dangling pointer\n- This results in a write to already-freed memory during the eviction process\n\n## Impact\n\n- **CWE-416 (Use-After-Free):** memory corruption when subsequent cache operations access freed node pointers in the linked list\n- **CWE-415 (Double Free):** potential heap corruption when the same memory is freed multiple times\n\nBoth types of undefined behavior can be invoked in safe Rust, but only if unwinding panics are enabled and `std::panic::catch_unwind` is used with key types that have potentially-panicking `Drop` implementations.\n\n## Fix\n\nFixed in `lru` 0.18.2 by detaching the node from the linked list before freeing it and dropping the key ([lru-rs#238](https://github.com/jeromefroe/lru-rs/pull/238)).","modified":"2026-08-11T11:15:06.101553049Z","published":"2026-05-12T12:00:00Z","database_specific":{"license":"CC0-1.0"},"references":[{"type":"PACKAGE","url":"https://crates.io/crates/lru"},{"type":"ADVISORY","url":"https://rustsec.org/advisories/RUSTSEC-2026-0253.html"},{"type":"WEB","url":"https://github.com/jeromefroe/lru-rs/pull/238"}],"affected":[{"package":{"name":"lru","ecosystem":"crates.io","purl":"pkg:cargo/lru"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.0.0-0"},{"fixed":"0.18.2"}]}],"ecosystem_specific":{"affected_functions":null,"affects":{"functions":[],"arch":[],"os":[]}},"database_specific":{"cvss":null,"informational":"unsound","categories":["memory-corruption"],"source":"https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0253.json"}}],"schema_version":"1.9.0"}