{"id":"GHSA-628h-q48j-jr6q","summary":"Phoenix: Long-poll NDJSON body splitting causes large memory allocation","details":"### Summary\n\nAn unauthenticated denial-of-service vulnerability in Phoenix's long-poll transport allows a remote client to allocate a large amount of memory with a HTTP request. A handful of concurrent requests can be sufficient to let the node run out of memory.\n\nSee also https://cna.erlef.org/cves/CVE-2026-32689.html.\n\n### Details\n\nThe unoptimised code path exists on the `application/x-ndjson` POST handling in the LongPoll transport. The endpoint requires only a session token, which any client can obtain by issuing a GET to the same URL with a matching `Origin` header, so exploitation is unauthenticated.\n\n### Impact\n\nAnyone who runs a LiveView app with a public Longpoll socket or uses a `Phoenix.Socket` with longpoll option.\nLongpoll has been enabled for newly generated Phoenix projects since Phoenix 1.7.11.","aliases":["CVE-2026-32689","EEF-CVE-2026-32689"],"modified":"2026-05-08T20:35:52.764218Z","published":"2026-05-08T20:24:15Z","database_specific":{"severity":"HIGH","github_reviewed":true,"github_reviewed_at":"2026-05-08T20:24:15Z","nvd_published_at":"2026-05-05T16:16:11Z","cwe_ids":["CWE-770"]},"references":[{"type":"WEB","url":"https://github.com/phoenixframework/phoenix/security/advisories/GHSA-628h-q48j-jr6q"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-32689"},{"type":"WEB","url":"https://github.com/phoenixframework/phoenix/commit/1a67c61ff9ce0a7711662ac7354861917a7c80f7"},{"type":"WEB","url":"https://github.com/phoenixframework/phoenix/commit/912ea181fd247c21dbcc49fb97d0053b947d81bf"},{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-32689.html"},{"type":"PACKAGE","url":"https://github.com/phoenixframework/phoenix"},{"type":"WEB","url":"https://osv.dev/vulnerability/EEF-CVE-2026-32689"}],"affected":[{"package":{"name":"phoenix","ecosystem":"Hex","purl":"pkg:hex/phoenix"},"ranges":[{"type":"SEMVER","events":[{"introduced":"1.7.0"},{"fixed":"1.7.22"}]}],"versions":["1.7.0","1.7.1","1.7.10","1.7.11","1.7.12","1.7.13","1.7.14","1.7.15","1.7.16","1.7.17","1.7.18","1.7.19","1.7.2","1.7.20","1.7.21","1.7.3","1.7.4","1.7.5","1.7.6","1.7.7","1.7.8","1.7.9"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-628h-q48j-jr6q/GHSA-628h-q48j-jr6q.json"}},{"package":{"name":"phoenix","ecosystem":"Hex","purl":"pkg:hex/phoenix"},"ranges":[{"type":"SEMVER","events":[{"introduced":"1.8.0"},{"fixed":"1.8.6"}]}],"versions":["1.8.0","1.8.1","1.8.2","1.8.3","1.8.4","1.8.5"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-628h-q48j-jr6q/GHSA-628h-q48j-jr6q.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"}]}