GHSA-29h2-jr22-frmh 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.
A malicious ERC-7984 token can extract private encrypted data from a vesting wallet by exploiting missing ACL checks on external handles.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is GHSA-29h2-jr22-frmh?
GHSA-29h2-jr22-frmh is a vulnerability in @openzeppelin/confidential-contracts, published on 25 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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).ERC7984transfer callback: fe0863af2c9dce7614acce98720a913bf6a767a5 (#428), with follow-up ee47edf189ab681cebdad18bfb53dee541987be2 (#431) permitting an uninitialized returned handle.
Which versions are affected by GHSA-29h2-jr22-frmh?
6 open source packages ship an affected version, including @openzeppelin/confidential-contracts.
| Package | Affected | Fixed in |
|---|---|---|
@openzeppelin/confidential-contracts npm | All versions | 0.3.2 |
@openzeppelin/confidential-contracts npm | All versions | 0.3.2 |
@openzeppelin/confidential-contracts npm | From 0.4.0-rc.0 | 0.4.2 |
@openzeppelin/confidential-contracts npm | From 0.4.0-rc.0 | 0.4.2 |
@openzeppelin/confidential-contracts npm | From 0.5.0-rc.0 | 0.5.2 |
@openzeppelin/confidential-contracts npm | From 0.5.0-rc.0 | 0.5.2 |
How do I fix GHSA-29h2-jr22-frmh?
Upgrade @openzeppelin/confidential-contracts to a fixed version for your release line: 0.3.2, 0.4.2 or 0.5.2.
Is GHSA-29h2-jr22-frmh being exploited?
There is no known exploitation of GHSA-29h2-jr22-frmh in the wild and no public exploit code.