Reported

September 2, 2026

Issued

September 22, 2026

Package

skiplist (crates.io)

Type

Vulnerability

Categories

• memory-corruption

Keywords

#memory-safety #use-after-free #double-free #panic-safety

Aliases

• GHSA-x6j6-3ffp-qrfr

References

• https://github.com/JP-Ellis/rust-skiplist/pull/334

Patched

• >=1.1.1

Affected Functions

Version

skiplist::ordered_skip_list::OrderedSkipList::clear

• <1.1.1

skiplist::ordered_skip_list::OrderedSkipList::dedup_by

• <1.1.1

skiplist::ordered_skip_list::OrderedSkipList::retain

• <1.1.1

skiplist::skip_list::SkipList::clear

• <1.1.1

skiplist::skip_list::SkipList::dedup_by

• <1.1.1

skiplist::skip_list::SkipList::retain

• <1.1.1

skiplist::skip_list::SkipList::retain_mut

• <1.1.1

skiplist::skip_map::SkipMap::clear

• <1.1.1

skiplist::skip_map::SkipMap::retain

• <1.1.1

Description

SkipList::clear drops the node chain and only then resets tail and len. The drop runs each element's Drop, and T carries no bounds excluding a panicking one. If it unwinds, tail still points at the freed node while len stays non-zero.

back(), back_mut(), last_key_value() and last() dereference tail through unsafe, so reading the container after the unwind is a use-after-free (CWE-416). Drop for SkipList calls Box::from_raw on self.head, which clear already destroyed, so dropping the container is a double free (CWE-415).

retain, retain_mut and dedup_by reach the same state through Node::filter_rebuild, which frees nodes and runs a user predicate before the caller commits tail and len. There the head links are left partially rewired, so traversal can also reach freed nodes.

Mitigation

Update to 1.1.1.

Advisory available under CC0-1.0 license.