{"id":"CVE-2026-77856","state":"PUBLISHED","title":"Unbounded atom creation from typed struct field names in AshTypescript field selector","description":"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.","publishedAt":"2026-09-01T02:08:46.189Z","updatedAt":"2026-09-01T14:49:22.592Z","severity":{"score":8.2,"label":"High","version":"4.0","vector":"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","source":"EEF"},"assigner":"EEF","products":["ash-project ash_typescript"],"affected":[{"vendor":"ash-project","product":"ash_typescript","packageName":"ash_typescript","packageURL":"pkg:hex/ash_typescript","defaultStatus":"unaffected","versions":[{"version":"0.11.0","status":"affected","lessThan":"0.18.0","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:ash-project:ash_typescript:*:*:*:*:*:*:*:*"],"modules":["'Elixir.AshTypescript.Rpc.FieldProcessing.FieldSelector'","'Elixir.AshTypescript.Rpc'"],"programFiles":["lib/ash_typescript/rpc/field_processing/field_selector.ex","lib/ash_typescript/rpc.ex"],"programRoutines":[{"name":"'Elixir.AshTypescript.Rpc.FieldProcessing.FieldSelector':resolve_typed_struct_field/2"},{"name":"'Elixir.AshTypescript.Rpc':run_action/3"}],"repo":"https://github.com/ash-project/ash_typescript"},{"vendor":"ash-project","product":"ash_typescript","packageName":"ash-project/ash_typescript","packageURL":"pkg:github/ash-project/ash_typescript","defaultStatus":"unaffected","versions":[{"version":"7c3d30896f2f9a54edea17e3787549776b1b288d","status":"affected","lessThan":"0ab5c83a7df28d51a6de1fb9b859a142b2b12919","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:ash-project:ash_typescript:*:*:*:*:*:*:*:*"],"modules":["'Elixir.AshTypescript.Rpc.FieldProcessing.FieldSelector'","'Elixir.AshTypescript.Rpc'"],"programFiles":["lib/ash_typescript/rpc/field_processing/field_selector.ex","lib/ash_typescript/rpc.ex"],"programRoutines":[{"name":"'Elixir.AshTypescript.Rpc.FieldProcessing.FieldSelector':resolve_typed_struct_field/2"},{"name":"'Elixir.AshTypescript.Rpc':run_action/3"}],"repo":"https://github.com/ash-project/ash_typescript"}],"references":["https://github.com/ash-project/ash_typescript/security/advisories/GHSA-rj47-h936-4cxw","https://cna.erlef.org/cves/CVE-2026-77856.html","https://osv.dev/vulnerability/EEF-CVE-2026-77856","https://github.com/ash-project/ash_typescript/commit/0ab5c83a7df28d51a6de1fb9b859a142b2b12919"],"weaknesses":["CWE-770"],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/77xxx/CVE-2026-77856.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-77856","state":"PUBLISHED","datePublished":"2026-09-01T02:08:46.189Z","dateUpdated":"2026-09-01T14:49:22.592Z","assignerShortName":"EEF","assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateReserved":"2026-08-30T17:30:01.406Z"},"containers":{"cna":{"title":"Unbounded atom creation from typed struct field names in AshTypescript field selector","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"ash-project","product":"ash_typescript","packageName":"ash_typescript","packageURL":"pkg:hex/ash_typescript","defaultStatus":"unaffected","versions":[{"version":"0.11.0","status":"affected","lessThan":"0.18.0","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:ash-project:ash_typescript:*:*:*:*:*:*:*:*"],"modules":["'Elixir.AshTypescript.Rpc.FieldProcessing.FieldSelector'","'Elixir.AshTypescript.Rpc'"],"programFiles":["lib/ash_typescript/rpc/field_processing/field_selector.ex","lib/ash_typescript/rpc.ex"],"programRoutines":[{"name":"'Elixir.AshTypescript.Rpc.FieldProcessing.FieldSelector':resolve_typed_struct_field/2"},{"name":"'Elixir.AshTypescript.Rpc':run_action/3"}],"repo":"https://github.com/ash-project/ash_typescript"},{"vendor":"ash-project","product":"ash_typescript","packageName":"ash-project/ash_typescript","packageURL":"pkg:github/ash-project/ash_typescript","defaultStatus":"unaffected","versions":[{"version":"7c3d30896f2f9a54edea17e3787549776b1b288d","status":"affected","lessThan":"0ab5c83a7df28d51a6de1fb9b859a142b2b12919","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:ash-project:ash_typescript:*:*:*:*:*:*:*:*"],"modules":["'Elixir.AshTypescript.Rpc.FieldProcessing.FieldSelector'","'Elixir.AshTypescript.Rpc'"],"programFiles":["lib/ash_typescript/rpc/field_processing/field_selector.ex","lib/ash_typescript/rpc.ex"],"programRoutines":[{"name":"'Elixir.AshTypescript.Rpc.FieldProcessing.FieldSelector':resolve_typed_struct_field/2"},{"name":"'Elixir.AshTypescript.Rpc':run_action/3"}],"repo":"https://github.com/ash-project/ash_typescript"}],"references":[{"url":"https://github.com/ash-project/ash_typescript/security/advisories/GHSA-rj47-h936-4cxw","tags":["related","vendor-advisory"]},{"url":"https://cna.erlef.org/cves/CVE-2026-77856.html","tags":["related"]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-77856","tags":["related"]},{"url":"https://github.com/ash-project/ash_typescript/commit/0ab5c83a7df28d51a6de1fb9b859a142b2b12919","tags":["patch"]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":8.2,"baseSeverity":"HIGH","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"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","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-770","description":"CWE-770 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resolve_typed_struct_field/2."}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:ash-project:ash_typescript:*:*:*:*:*:*:*:*","versionEndExcluding":"0.18.0","versionStartIncluding":"0.11.0","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"AND"}],"credits":[{"lang":"en","type":"finder","value":"Peter Ullrich"},{"lang":"en","type":"reporter","value":"Peter Ullrich"},{"lang":"en","type":"remediation developer","value":"Torkild Gundersen Kjevik / Ash Project"},{"lang":"en","type":"coordinator","value":"Jonatan Männchen / EEF"}],"impacts":[{"capecId":"CAPEC-130","descriptions":[{"lang":"en","value":"CAPEC-130 Excessive Allocation"}]}],"source":{"discovery":"EXTERNAL"}},"adp":[{"title":"CISA ADP 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