# RUSTSEC-2026-0131: Double-free in `Chomp::inner()`

> A double-free vulnerability in the Chomp library allows attackers to trigger undefined behavior, potentially leading to code execution or crashes via safe public APIs.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Not stated
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 May 2026

## What is RUSTSEC-2026-0131?

RUSTSEC-2026-0131 is an use after free vulnerability in bitchomp, published on 2 May 2026. 

### Official description

`Chomp::inner()` uses `std::ptr::read_unaligned` to move out the value from a
raw pointer. If the original value is an owned type (e.g. `Box`), calling
`inner()` moves out the ownership, but the original variable will still be
dropped at the end of its scope. This causes the same heap memory to be freed
twice, resulting in a double-free and undefined behavior.

This can be triggered through safe public APIs — `Chomp::new()` and
`Chomp::inner()` — with no `unsafe` required from the caller.

## Which versions are affected by RUSTSEC-2026-0131?

1 open source package ship an affected version, including bitchomp.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `bitchomp` | crates.io | From 0.0.0-0 | None |

## How do I fix RUSTSEC-2026-0131?

No fix has been published for RUSTSEC-2026-0131 yet. Limit exposure of the affected software until one is available.

## Is RUSTSEC-2026-0131 being exploited?

There is no known exploitation of RUSTSEC-2026-0131 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for RUSTSEC-2026-0131 and fix it if it is affected.

What it is: RUSTSEC-2026-0131 is an use after free vulnerability in bitchomp, published on 2 May 2026. 
Exploitation: There is no known exploitation of RUSTSEC-2026-0131 in the wild and no public exploit code.

Affected packages and fixed versions:
- bitchomp (crates.io): affected from 0.0.0-0; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/RUSTSEC-2026-0131/ (Markdown: https://insights.sbomify.com/RUSTSEC-2026-0131/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/RUSTSEC-2026-0131

---
From sbomify Insights: https://insights.sbomify.com/RUSTSEC-2026-0131/
Summaries are generated and may contain mistakes; the official description above is the record.