# RUSTSEC-2026-0018: `rpc-check` was removed from crates.io for malicious code

> A malicious typosquatted Rust crate exfiltrates user credentials, requiring developers to audit dependencies and remove the package.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Feb 2026

## What is RUSTSEC-2026-0018?

RUSTSEC-2026-0018 is a vulnerability in rpc-check, published on 24 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

This is part of an ongoing campaign to attempt to typosquat crates in the
[`polymarket-client-sdk`](https://crates.io/crates/polymarket-client-sdk)
ecosystem to exfiltrate user credentials.

The malicious crate had 6 versions published from 2026-02-20 onwards and had no
evidence of actual usage. There were no crates depending on this crate on
crates.io.

Thanks to Eren for finding and reporting this to the Rust security response
working group, and to Emily Albini for co-ordinating with the crates.io team.

The crates.io team advises anyone developing with Polymarket to review
dependencies carefully. We are investigating ways to mitigate this attacker who
appears to be very motivated to steal Polymarket credentials.

## Which versions are affected by RUSTSEC-2026-0018?

1 open source package ship an affected version, including rpc-check.


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

## How do I fix RUSTSEC-2026-0018?

No fix has been published for RUSTSEC-2026-0018 yet. Limit exposure of the affected software until one is available.

## Is RUSTSEC-2026-0018 being exploited?

There is no known exploitation of RUSTSEC-2026-0018 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for RUSTSEC-2026-0018 and fix it if it is affected.

What it is: RUSTSEC-2026-0018 is a vulnerability in rpc-check, published on 24 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of RUSTSEC-2026-0018 in the wild and no public exploit code.

Affected packages and fixed versions:
- rpc-check (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-2026-0018/ (Markdown: https://insights.sbomify.com/RUSTSEC-2026-0018/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/RUSTSEC-2026-0018

---
From sbomify Insights: https://insights.sbomify.com/RUSTSEC-2026-0018/
Summaries are generated and may contain mistakes; the official description above is the record.