# Use-after-free when a future's \`Drop\` panics while the container is dropped

Advisory record · `GHSA-8gw6-724c-9h38`

- **Identifiers:** `GHSA-8gw6-724c-9h38` · `RUSTSEC-2026-0298`
- **State:** Confirmed
- **Severity:** No CVSS score
- **Critical:** No
- **Published:** 12 Sept 2026
- **Updated:** 22 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 12 Sept 2026, 12:00 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `unicycle` (crates.io): affected `>=0.0.0-0, <0.10.3`; fixed in `0.10.3`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Versions of the unicycle crate before 0.10.3 are affected by a use-after-free. If a future's Drop implementation panics while the container is being dropped, the storage's length is never committed, and a second cleanup pass then reads memory that was already freed. An attacker needs no special method call, only the ability to get a panicking future dropped inside the container. Upgrade to unicycle 0.10.3.

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

No source has published a CVSS score for this record yet.

- **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-2026-0298)

## Sources

- [GitHub Advisory Database: GHSA-8gw6-724c-9h38](https://github.com/advisories/GHSA-8gw6-724c-9h38)
- [OSV: GHSA-8gw6-724c-9h38](https://osv.dev/vulnerability/GHSA-8gw6-724c-9h38)
- <https://crates.io/crates/unicycle>
- <https://rustsec.org/advisories/RUSTSEC-2026-0298.html>
- <https://github.com/udoprog/unicycle/commit/4f1492a266824f8aa66fd6b27fa6188bf826bdfd>

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 (<https://api.agentprime.io/mcp>), 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: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-8gw6-724c-9h38>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-8gw6-724c-9h38/>. Everything for agents: <https://agentprime.io/llms.txt>.
