CVE-2026-77856
Unbounded atom creation from typed struct field names in AshTypescript field selector
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
8.2
Unbounded atom creation from typed struct field names in AshTypescript field selector
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.
- Record
CVE-2026-77856- CVSS 4.0
- 8.2 High
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 - Weakness
- CWE-770
- Updated
- 2026-11-02
EUVDEUVD-2026-68924
8.2
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.
- Record
EUVD-2026-68924- CVSS 4.0
- 8.2 High
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 - Updated
- 2026-11-02
NVD
8.2
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.
- Record
CVE-2026-77856- CVSS 4.0
- 8.2 High
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-770
- Updated
- 2026-11-02
OSV
8.2
Unbounded atom creation from typed struct field names in AshTypescript field selector
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.
- Record
CVE-2026-77856- CVSS 4.0
- 8.2 High
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 - Weakness
- CWE-770
- Updated
- 2026-11-02
OSVEEF-CVE-2026-77856
8.2
Unbounded atom creation from typed struct field names in AshTypescript field selector
Summary
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.
Configurations
The 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.
- Record
EEF-CVE-2026-77856- CVSS 4.0
- 8.2 High
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 - Weakness
- CWE-770
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
ash_typescriptHex |
0.11.0 up to 0.18.0, plus listed versions 0.11.10.11.20.11.30.11.40.11.5 Show 20 moreShow less0.11.60.12.00.12.10.13.00.13.10.13.20.14.00.14.10.14.20.14.30.14.40.15.00.15.10.15.20.15.30.16.00.17.00.17.10.17.20.17.3 |
0.18.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-77856 is a high vulnerability (CVSS 8.2) in Ash-project Ash Typescript, published September 1, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.55%, the 46th percentile. Fixed in ash_typescript 0.18.0.