# GHSA-9v25-r5q2-2p6w: Candy Machine Set Collection During Mint Missing Check

> Attackers can mint NFTs to arbitrary collections in Candy Machine V2 by bypassing validation checks, allowing unauthorized collection membership.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Dec 2022

## What is GHSA-9v25-r5q2-2p6w?

GHSA-9v25-r5q2-2p6w is a vulnerability in mpl-candy-machine, published on 12 Dec 2022. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A problem with Candy Machine V2 allow minting NFTs to an arbitrary collection due to a missing check.

Here is a description of the exploit:
Details:
Here is the tx/ix to exploit:
Transaction:
Ix 1: candy_machine v2, mint_nft, passing in empty metadata -1
Ix 2: custom handler, 0
		cpi A --> token_metadata create_metadata_account, creates NFT
		cpi B --> candy_machine v2, set_collection_during_mint
Ix 1 passes our first check for empty metadata, but eventually will hit a bot tax and return Ok.  We do have a CPI check in this function but even if we hit that or moved it to the top, it returns Ok as a bot tax and still enables the issue.
Ix 2, cpi A is Ok and mints an arbitrary NFT.
Ix 2, cpi B checks the previous instruction using index_relative_to_current-1.  This turns out to be Ix 1 which was Ok, so then your newly minted arbitrary NFT is successfully added to the collection.
Conclusion:
Candy machine could be out of NFTs and it still works.  If the CM is closed, (we think?) it doesn't get to the check.
The fix needs to be in set_collection_during_mint that current program ID id candy_machine_v2.  It checks previous program ID but doesn't check current.

NOTE: THIS DOES NOT AFFECT Cmv3

## Which versions are affected by GHSA-9v25-r5q2-2p6w?

2 open source packages ship an affected version, including mpl-candy-machine.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mpl-candy-machine` | crates.io | From 4.5.0 | 4.5.1 |
| `mpl-candy-machine` | crates.io | From 4.5.0 | 4.5.1 |

## How do I fix GHSA-9v25-r5q2-2p6w?

Upgrade mpl-candy-machine to 4.5.1 or later.

## Is GHSA-9v25-r5q2-2p6w being exploited?

There is no known exploitation of GHSA-9v25-r5q2-2p6w in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-9v25-r5q2-2p6w and fix it if it is affected.

What it is: GHSA-9v25-r5q2-2p6w is a vulnerability in mpl-candy-machine, published on 12 Dec 2022. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of GHSA-9v25-r5q2-2p6w in the wild and no public exploit code.

Affected packages and fixed versions:
- mpl-candy-machine (crates.io): affected from 4.5.0; fixed in 4.5.1
- mpl-candy-machine (crates.io): affected from 4.5.0; fixed in 4.5.1

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/GHSA-9v25-r5q2-2p6w/ (Markdown: https://insights.sbomify.com/GHSA-9v25-r5q2-2p6w/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-9v25-r5q2-2p6w

---
From sbomify Insights: https://insights.sbomify.com/GHSA-9v25-r5q2-2p6w/
Summaries are generated and may contain mistakes; the official description above is the record.