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High · 8.2 CVE-2026-77856 EEF-CVE-2026-77856EUVD-2026-68924GHSA-rj47-h936-4cxw

Unbounded atom creation from typed struct field names in AshTypescript field selector

Published Sep 1, 2026 · Updated Sep 1, 2026 · Assigned by EEF

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.

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.

This issue affects ash_typescript: from 0.11.0 before 0.18.0.

Affected products

VendorProductAffectedFixed
ash-project ash_typescript 0.11.0 – < 0.18.0 0.18.0

Affected packages

EcosystemPackageAffectedFixedRecord
Hex ash_typescript >= 0.11.0, < 0.18.0 0.18.0 EEF-CVE-2026-77856

References