{"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","slug":"GHSA-29h2-jr22-frmh","body":"## Overview\n\n### Impact\n\nTwo locations consume an encrypted handle returned by an untrusted external party and use it without verifying that the party is ACL-authorized on it.\n\n#### `VestingWalletConfidential`\n\nMalicious 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.\n\nEffectively, 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.\n\n#### ERC7984\n\nOn a transfer with callback, `ERC7984` uses the `ebool` returned by the\nrecipient's `IERC7984Receiver.onConfidentialTransferReceived` to drive the refund\nlogic, without checking that the recipient has ACL access to it. A malicious recipient\ncan return any `ebool` the token has access to and recover its plaintext from the\nrefund result, which the token grants the caller access to. The leak is limited\nto `ebool` handles (the value is only used as an `FHE.select` condition), and\nthere is no loss of funds.\n\n### Patches\n\nBoth issues were fixed in the same patch releases: v0.5.2, v0.4.2, v0.3.2\n\n- `VestingWalletConfidential`: 93e75ceed2b9648f53f9d133f431064353456805 (#423).\n- `ERC7984` transfer callback: fe0863af2c9dce7614acce98720a913bf6a767a5 (#428), with follow-up ee47edf189ab681cebdad18bfb53dee541987be2 (#431) permitting an uninitialized returned handle.\n\n## Affected packages\n\n- `@openzeppelin/confidential-contracts < 0.3.2`\n- `@openzeppelin/confidential-contracts >= 0.4.0-rc.0, < 0.4.2`\n- `@openzeppelin/confidential-contracts >= 0.5.0-rc.0, < 0.5.2`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `@openzeppelin/confidential-contracts 0.3.2`\n- `@openzeppelin/confidential-contracts 0.4.2`\n- `@openzeppelin/confidential-contracts 0.5.2`","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}