# Use-after-free from a comparator that answers inconsistently Advisory record · `GHSA-cc53-p78w-23w9` - **Identifiers:** `GHSA-cc53-p78w-23w9` · `RUSTSEC-2026-0409` - **State:** Confirmed - **Severity:** CVSS 4.0, no score published - **Critical:** No - **Published:** 24 Oct 2026 - **Updated:** 26 Oct 2026 - **Reviewed by a person:** No Published by the GitHub Advisory Database at 24 Oct 2026, 12:00 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Affected packages - `skiplist` (crates.io): affected `>=0.0.0-0, <1.3.0`; fixed in `1.3.0` ## Machine-written summary Summary written by Claude Haiku from the source advisory. Not reviewed by a person. > Versions of the skiplist crate before 1.3.0 can free a node that is still linked when a Comparator or Ord implementation gives inconsistent answers for the same pair of values during one mutating call, such as insert, take_first, take or remove. A later call then reads the freed memory. No unsafe code is needed: a safe Ord implementation with the default comparator can trigger it, but only if the comparison is stateful or non-deterministic. Upgrade to skiplist 1.3.0 or later, where such contradictions cause a panic before the collection is modified. Written 3 Nov 2026. ## Not analysed yet We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check. ## Severity and exploitation - Score not published, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N`, from OSV - **CISA KEV:** Not listed. - **EPSS:** No score. ## Timeline - 31 Oct 2026, 14:24 UTC: First seen by agentprime - 31 Oct 2026, 14:24 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/RUSTSEC-2026-0409) ## Sources - [GitHub Advisory Database: GHSA-cc53-p78w-23w9](https://github.com/advisories/GHSA-cc53-p78w-23w9) - [OSV: GHSA-cc53-p78w-23w9](https://osv.dev/vulnerability/GHSA-cc53-p78w-23w9) - - - Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code. ## Check whether this affects you A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet. - With the agentprime MCP server (), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: - In a browser: reads your lockfile in the browser, never uploading it. - Whether it touches your code, with file and line: the Claude Code plugin, - As JSON: , or `POST https://api.agentprime.io/v1/match` with your packages () --- The web page: . Everything for agents: .