{"id":"GHSA-29h2-jr22-frmh","summary":"OpenZeppelin Confidential Contracts `VestingWalletConfidential`: a malicious ERC-7984 token is able to extract private data from the vesting wallet","details":"### 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.","modified":"2026-09-25T19:45:10.310263130Z","published":"2026-09-25T19:31:08Z","database_specific":{"github_reviewed_at":"2026-09-25T19:31:08Z","nvd_published_at":null,"cwe_ids":["CWE-284"],"severity":"HIGH","github_reviewed":true},"references":[{"type":"WEB","url":"https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/security/advisories/GHSA-29h2-jr22-frmh"},{"type":"WEB","url":"https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/pull/423"},{"type":"WEB","url":"https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/pull/428"},{"type":"WEB","url":"https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/pull/431"},{"type":"WEB","url":"https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/commit/93e75ceed2b9648f53f9d133f431064353456805"},{"type":"WEB","url":"https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/commit/ee47edf189ab681cebdad18bfb53dee541987be2"},{"type":"WEB","url":"https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/commit/fe0863af2c9dce7614acce98720a913bf6a767a5"},{"type":"PACKAGE","url":"https://github.com/OpenZeppelin/openzeppelin-confidential-contracts"},{"type":"WEB","url":"https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/releases/tag/v0.3.2"},{"type":"WEB","url":"https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/releases/tag/v0.4.2"},{"type":"WEB","url":"https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/releases/tag/v0.5.2"}],"affected":[{"package":{"name":"@openzeppelin/confidential-contracts","ecosystem":"npm","purl":"pkg:npm/%40openzeppelin/confidential-contracts"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.3.2"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-29h2-jr22-frmh/GHSA-29h2-jr22-frmh.json"}},{"package":{"name":"@openzeppelin/confidential-contracts","ecosystem":"npm","purl":"pkg:npm/%40openzeppelin/confidential-contracts"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.4.0-rc.0"},{"fixed":"0.4.2"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-29h2-jr22-frmh/GHSA-29h2-jr22-frmh.json"}},{"package":{"name":"@openzeppelin/confidential-contracts","ecosystem":"npm","purl":"pkg:npm/%40openzeppelin/confidential-contracts"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.5.0-rc.0"},{"fixed":"0.5.2"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-29h2-jr22-frmh/GHSA-29h2-jr22-frmh.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}