{"id":"GHSA-677m-j7p3-52f9","summary":"socket.io allows an unbounded number of binary attachments","details":"### Impact\n\nA specially crafted Socket.IO packet can make the server wait for a large number of binary attachments and buffer them, which can be exploited to make the server run out of memory.\n\n### Patches\n\n| Version range    | Used by                                    | Fixed version |\n|------------------|--------------------------------------------|---------------|\n| `\u003e=4.0.0 \u003c4.2.6` | `socket.io@4.x` and `socket.io-client@4.x` | `4.2.6`       |\n| `\u003e=3.4.0 \u003c3.4.4` | `socket.io@2.x`                            | `3.4.4`       |\n| `\u003c3.3.5`         | `socket.io-client@2.x`                     | `3.3.5`       |\n\n### Workarounds\n\nThere is no known workaround except upgrading to a safe version.\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n\n- Open a discussion [here](https://github.com/socketio/socket.io/discussions)","aliases":["CVE-2026-33151"],"modified":"2026-07-17T21:12:53.653495834Z","published":"2026-03-18T17:26:14Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2026-03-18T17:26:14Z","nvd_published_at":"2026-03-20T21:17:15Z","cwe_ids":["CWE-754"],"severity":"HIGH"},"references":[{"type":"WEB","url":"https://github.com/socketio/socket.io/security/advisories/GHSA-677m-j7p3-52f9"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33151"},{"type":"WEB","url":"https://github.com/socketio/socket.io/commit/719f9ebab0772ffb882bd614b387e585c1aa75d4"},{"type":"WEB","url":"https://github.com/socketio/socket.io/commit/9d39f1f080510f036782f2177fac701cc041faaf"},{"type":"WEB","url":"https://github.com/socketio/socket.io/commit/b25738c416c4e32fbff62ee182afa8f6d0dacf78"},{"type":"PACKAGE","url":"https://github.com/socketio/socket.io"}],"affected":[{"package":{"name":"socket.io-parser","ecosystem":"npm","purl":"pkg:npm/socket.io-parser"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.3.5"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-677m-j7p3-52f9/GHSA-677m-j7p3-52f9.json"}},{"package":{"name":"socket.io-parser","ecosystem":"npm","purl":"pkg:npm/socket.io-parser"},"ranges":[{"type":"SEMVER","events":[{"introduced":"3.4.0"},{"fixed":"3.4.4"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-677m-j7p3-52f9/GHSA-677m-j7p3-52f9.json"}},{"package":{"name":"socket.io-parser","ecosystem":"npm","purl":"pkg:npm/socket.io-parser"},"ranges":[{"type":"SEMVER","events":[{"introduced":"4.0.0"},{"fixed":"4.2.6"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-677m-j7p3-52f9/GHSA-677m-j7p3-52f9.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"}]}