GitHub Advisoryadvisory · npm
GHSA-29h2-jr22-frmh OpenZeppelin Confidential Contracts `VestingWalletConfidential`: a malicious ERC-7984 token is able to extract private data from the vesting wallet
HIGH
Official page ↗
- Ecosystem
- npm
- Packages
- @openzeppelin/confidential-contracts
- Severity
- High
- CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- Weaknesses
- CWE-284
- Reviewed
- 2026-09-25
Affected packages
• npm @openzeppelin/confidential-contracts: < 0.3.2 → fixed in 0.3.2
• npm @openzeppelin/confidential-contracts: >= 0.4.0-rc.0, < 0.4.2 → fixed in 0.4.2
• npm @openzeppelin/confidential-contracts: >= 0.5.0-rc.0, < 0.5.2 → fixed in 0.5.2
Description
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.
Related
Weakness · CWE (1)
- CWE-284 Improper Access Control weakness
References
- https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/security/advisories/GHSA-29h2-jr22-frmh web
- https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/pull/423 web
- https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/pull/428 web
- https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/pull/431 web
- https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/commit/93e75ceed2b9648f53f9d133f431064353456805 web
- https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/commit/ee47edf189ab681cebdad18bfb53dee541987be2 web
- https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/commit/fe0863af2c9dce7614acce98720a913bf6a767a5 web
- https://github.com/OpenZeppelin/openzeppelin-confidential-contracts package
- https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/releases/tag/v0.3.2 web
- https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/releases/tag/v0.4.2 web
- https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/releases/tag/v0.5.2 web