{"id":"CVE-2026-77856","summary":"Unbounded atom creation from typed struct field names in AshTypescript field selector","details":"Allocation 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\nresolve_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.","aliases":["EEF-CVE-2026-77856","GHSA-rj47-h936-4cxw"],"modified":"2026-09-02T03:47:32.207055373Z","published":"2026-09-01T02:08:46.189Z","database_specific":{"cna_assigner":"EEF","cwe_ids":["CWE-770"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77856.json","unresolved_ranges":[{"extracted_events":[{"introduced":"7c3d30896f2f9a54edea17e3787549776b1b288d"},{"fixed":"0ab5c83a7df28d51a6de1fb9b859a142b2b12919"}],"source":"AFFECTED_FIELD"}]},"references":[{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-77856.html"},{"type":"WEB","url":"https://github.com"},{"type":"WEB","url":"https://osv.dev/vulnerability/EEF-CVE-2026-77856"},{"type":"WEB","url":"https://repo.hex.pm"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77856.json"},{"type":"ADVISORY","url":"https://github.com/ash-project/ash_typescript/security/advisories/GHSA-rj47-h936-4cxw"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-77856"},{"type":"FIX","url":"https://github.com/ash-project/ash_typescript/commit/0ab5c83a7df28d51a6de1fb9b859a142b2b12919"},{"type":"PACKAGE","url":"https://github.com/ash-project/ash_typescript"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/ash-project/ash_typescript","events":[{"introduced":"a42177bfc4acd27bb2f25372da9b3de467d6bcae"},{"fixed":"808e4b17ee821a8dac98bda5bf01da0fe1b69d41"},{"fixed":"0ab5c83a7df28d51a6de1fb9b859a142b2b12919"}],"database_specific":{"extracted_events":[{"introduced":"0.11.0"},{"fixed":"0.18.0"}],"source":["DESCRIPTION","REFERENCES"]}}],"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://storage.googleapis.com/cve-osv-conversion/osv-output/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"}]}