{"id":"EEF-CVE-2026-47067","summary":"Atom table exhaustion via unrecognized URL schemes in hackney","details":"## Summary\n\nAllocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding. The URL parser in src/hackney_url.erl converts every unrecognized URL scheme to a permanent BEAM atom via binary_to_atom/2. BEAM atoms are never garbage-collected and the atom table defaults to a hard limit of 1,048,576 entries. An attacker who can supply URLs with attacker-chosen scheme prefixes — directly as request targets, as configured webhook URLs, or via Location headers followed during redirects — can exhaust the atom table and crash the entire BEAM VM with system_limit.\n\nThis issue affects hackney: from 2.0.0 before 4.0.1.","aliases":["CVE-2026-47067","GHSA-9653-rcfr-5c62"],"modified":"2026-05-27T16:00:18.977936995Z","published":"2026-05-25T14:00:48.507Z","database_specific":{"cpe_ids":["cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*"],"cwe_ids":["CWE-770"],"capec_ids":["CAPEC-125"]},"references":[{"type":"ADVISORY","url":"https://github.com/benoitc/hackney/security/advisories/GHSA-9653-rcfr-5c62"},{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-47067.html"},{"type":"FIX","url":"https://github.com/benoitc/hackney/commit/31f6f0e27e096ad88743dfded4f030a3ee74972e"},{"type":"PACKAGE","url":"https://hex.pm/packages/hackney"}],"affected":[{"package":{"name":"hackney","ecosystem":"Hex","purl":"pkg:hex/hackney"},"ranges":[{"type":"SEMVER","events":[{"introduced":"2.0.0"},{"fixed":"4.0.1"}]}],"versions":["2.0.0","2.0.1","3.0.0","3.0.1","3.0.2","3.0.3","3.1.0","3.1.1","3.1.2","3.2.0","3.2.1","4.0.0"],"database_specific":{"source":"https://cna.erlef.org/osv/EEF-CVE-2026-47067.json"}},{"ranges":[{"type":"GIT","repo":"https://github.com/benoitc/hackney","events":[{"introduced":"d9713695c0d99855d12c73fd8a0b4be0543950c4"},{"fixed":"31f6f0e27e096ad88743dfded4f030a3ee74972e"}]}],"versions":["4.0.0","3.2.1","3.2.0","3.1.2","3.1.1","3.1.0","3.0.3","3.0.2","3.0.1","2.0.1","2.0.0"],"database_specific":{"source":"https://cna.erlef.org/osv/EEF-CVE-2026-47067.json"}}],"schema_version":"1.7.5","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"}],"credits":[{"name":"Peter Ullrich","type":"FINDER"},{"name":"Benoit Chesneau","type":"REMEDIATION_DEVELOPER"},{"name":"Jonatan Männchen / EEF","type":"ANALYST"}]}