Unbounded atom creation from typed struct field names in AshTypescript field selector (CVE-2026-77856) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-77856

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

Answer in brief

CVE-2026-77856 records a Unknown severity vulnerability in Unbounded atom creation from typed struct field names in AshTypescript field selector. The current sources do not mark it as known exploited. The current feed maps ash-project/ash_typescript (generic), ash-project/ash_typescript (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 1, 2026Updated Sep 1, 2026Source checked Sep 1, 2026First seen by HOL Sep 1, 2026Material review Sep 1, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps ash-project/ash_typescript (generic), ash-project/ash_typescript (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
ash-project/ash_typescriptgeneric	>=0.11.0 <0.18.0	0.18.0
ash-project/ash_typescriptgeneric	>=7c3d30896f2f9a54edea17e3787549776b1b288d <0ab5c83a7df28d51a6de1fb9b859a142b2b12919	0ab5c83a7df28d51a6de1fb9b859a142b2b12919

Recommended response

Check inventory. Check lockfiles and deployed manifests for ash-project/ash_typescript, ash-project/ash_typescript.
Review the reported fix. Update ash-project/ash_typescript to 0.18.0; ash-project/ash_typescript to 0ab5c83a7df28d51a6de1fb9b859a142b2b12919 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 1, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.