---
id: GHSA-29h2-jr22-frmh
title: >-
  OpenZeppelin Confidential Contracts `VestingWalletConfidential`: a malicious
  ERC-7984 token is able to extract private data from the vesting wallet
summary: >-
  OpenZeppelin Confidential Contracts `VestingWalletConfidential`: a malicious
  ERC-7984 token is able to extract private data from the vesting wallet
severity: high
cwe:
  - CWE-284
vendor: openzeppelin
product: '@openzeppelin/confidential-contracts'
ecosystem: npm
affected:
  - '@openzeppelin/confidential-contracts < 0.3.2'
  - '@openzeppelin/confidential-contracts >= 0.4.0-rc.0, < 0.4.2'
  - '@openzeppelin/confidential-contracts >= 0.5.0-rc.0, < 0.5.2'
patched:
  - '@openzeppelin/confidential-contracts 0.3.2'
  - '@openzeppelin/confidential-contracts 0.4.2'
  - '@openzeppelin/confidential-contracts 0.5.2'
published: '2026-09-25'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T19:31:09Z'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-29h2-jr22-frmh'
references:
  - url: >-
      https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/security/advisories/GHSA-29h2-jr22-frmh
  - url: >-
      https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/pull/423
  - url: >-
      https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/pull/428
  - url: >-
      https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/pull/431
  - url: >-
      https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/commit/93e75ceed2b9648f53f9d133f431064353456805
  - url: >-
      https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/commit/ee47edf189ab681cebdad18bfb53dee541987be2
  - url: >-
      https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/commit/fe0863af2c9dce7614acce98720a913bf6a767a5
  - url: >-
      https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/releases/tag/v0.3.2
  - url: >-
      https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/releases/tag/v0.4.2
  - url: >-
      https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/releases/tag/v0.5.2
  - url: 'https://github.com/advisories/GHSA-29h2-jr22-frmh'
tags:
  - ghsa
  - npm
ingestedAt: '2026-09-25T20:17:49.422Z'
---

## Overview

### Impact

Two locations consume an encrypted handle returned by an untrusted external party and use it without verifying that the party is ACL-authorized on it.

#### `VestingWalletConfidential`

Malicious users can call `release` with a malicious token. This token could return an alternative handle on `confidentialBalanceOf`, which represents the balance of the vesting wallet on an alternative ERC-7984 token (or any other handle that the vesting wallet has access to). The vesting wallet does not check that the token has ACL access and grants access to a new handle derived from the returned handle.

Effectively, this bug allows a malicious user to gain information about any private `euint64` handle that the vesting wallet has access to via a malicious ERC-7984 token. There is no loss of funds.

#### ERC7984

On a transfer with callback, `ERC7984` uses the `ebool` returned by the
recipient's `IERC7984Receiver.onConfidentialTransferReceived` to drive the refund
logic, without checking that the recipient has ACL access to it. A malicious recipient
can return any `ebool` the token has access to and recover its plaintext from the
refund result, which the token grants the caller access to. The leak is limited
to `ebool` handles (the value is only used as an `FHE.select` condition), and
there is no loss of funds.

### Patches

Both issues were fixed in the same patch releases: v0.5.2, v0.4.2, v0.3.2

- `VestingWalletConfidential`: 93e75ceed2b9648f53f9d133f431064353456805 (#423).
- `ERC7984` transfer callback: fe0863af2c9dce7614acce98720a913bf6a767a5 (#428), with follow-up ee47edf189ab681cebdad18bfb53dee541987be2 (#431) permitting an uninitialized returned handle.

## Affected packages

- `@openzeppelin/confidential-contracts < 0.3.2`
- `@openzeppelin/confidential-contracts >= 0.4.0-rc.0, < 0.4.2`
- `@openzeppelin/confidential-contracts >= 0.5.0-rc.0, < 0.5.2`

## Remediation

Upgrade to a patched release:

- `@openzeppelin/confidential-contracts 0.3.2`
- `@openzeppelin/confidential-contracts 0.4.2`
- `@openzeppelin/confidential-contracts 0.5.2`