{"id":"EEF-CVE-2026-77856","summary":"Unbounded atom creation from typed struct field names in AshTypescript field selector","details":"## Summary\n\nAllocation of Resources Without Limits or Throttling vulnerability in ash-project ash_typescript allows an unauthenticated attacker to exhaust the BEAM atom table and abort the node via client-supplied typed struct field names.\n\n`resolve_typed_struct_field/2` in `lib/ash_typescript/rpc/field_processing/field_selector.ex` looks a client-supplied field name up in the typed struct's reverse map and, when it finds no match, falls back to `String.to_atom/1`. Because this runs before any field-existence check, an unresolvable name mints a permanent atom rather than being rejected as unknown. Atoms are never garbage collected, so a request carrying many distinct names on a typed struct field grows the atom table until the VM aborts at its limit.\n\nThis issue affects ash_typescript: from 0.11.0 before 0.18.0.\n\n## Configurations\n\nThe application exposes an AshTypescript RPC endpoint over HTTP and has at least one resource field backed by an `Ash.TypedStruct`, so that client-supplied names reach `resolve_typed_struct_field/2`.","aliases":["CVE-2026-77856","GHSA-rj47-h936-4cxw"],"modified":"2026-09-08T03:45:06.999521122Z","published":"2026-09-01T02:08:46.189Z","database_specific":{"capec_ids":["CAPEC-130"],"cpe_ids":["cpe:2.3:a:ash-project:ash_typescript:*:*:*:*:*:*:*:*"],"cwe_ids":["CWE-770"]},"references":[{"type":"ADVISORY","url":"https://github.com/ash-project/ash_typescript/security/advisories/GHSA-rj47-h936-4cxw"},{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-77856.html"},{"type":"FIX","url":"https://github.com/ash-project/ash_typescript/commit/0ab5c83a7df28d51a6de1fb9b859a142b2b12919"},{"type":"PACKAGE","url":"https://hex.pm/packages/ash_typescript"}],"affected":[{"package":{"name":"ash_typescript","ecosystem":"Hex","purl":"pkg:hex/ash_typescript"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.11.0"},{"fixed":"0.18.0"}]}],"versions":["0.11.0","0.11.1","0.11.2","0.11.3","0.11.4","0.11.5","0.11.6","0.12.0","0.12.1","0.13.0","0.13.1","0.13.2","0.14.0","0.14.1","0.14.2","0.14.3","0.14.4","0.15.0","0.15.1","0.15.2","0.15.3","0.16.0","0.17.0","0.17.1","0.17.2","0.17.3"],"database_specific":{"source":"https://cna.erlef.org/osv/EEF-CVE-2026-77856.json"}},{"ranges":[{"type":"GIT","repo":"https://github.com/ash-project/ash_typescript","events":[{"introduced":"7c3d30896f2f9a54edea17e3787549776b1b288d"},{"fixed":"0ab5c83a7df28d51a6de1fb9b859a142b2b12919"}]}],"versions":["v0.15.0","v0.15.3","v0.15.2","v0.15.1","v0.14.4","v0.14.3","v0.14.2","v0.14.1","v0.14.0","v0.13.2","v0.13.1","v0.13.0","v0.12.1","v0.12.0","v0.11.6","v0.11.5","v0.11.4","v0.11.3","v0.11.2","v0.11.1","v0.11.0"],"database_specific":{"source":"https://cna.erlef.org/osv/EEF-CVE-2026-77856.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"}],"credits":[{"name":"Peter Ullrich","type":"FINDER"},{"name":"Peter Ullrich","type":"REPORTER"},{"name":"Torkild Gundersen Kjevik / Ash Project","type":"REMEDIATION_DEVELOPER"},{"name":"Jonatan Männchen / EEF","type":"COORDINATOR"}]}