CVE-2026-94201
- Source
- https://cve.org/CVERecord?id=CVE-2026-94201
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-94201.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-94201
- Aliases
- Published
- 2026-10-05T19:19:51Z
- Modified
- 2026-10-10T02:47:31Z
- Severity
-
- 8.2 (High) CVSS_V4 - 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 CVSS Calculator
- Summary
- Filtering an :atom attribute with unsafe_to_atom? can exhaust the BEAM atom table in Ash
- Details
-
Ash stores :atom-typed attributes as strings and compares them as strings. When such an attribute is referenced in a filter, the comparison value is coerced through Ash.Type.Atom. Because the type defined no coerce/2 callback, coercion fell back to the default (cast_input/2), which calls String.to_atom/1 when the attribute is configured with the unsafe_to_atom?: true constraint.
Filtering such an attribute with attacker-controlled strings therefore interned a new, permanent atom for every distinct value. Atoms are never garbage collected and the BEAM caps the atom table, so an actor who can supply filter values for a public, filterable :atom attribute declared with unsafe_to_atom?: true can exhaust the atom table and crash the node (denial of service). AshPaperTrail is a notable example: its version resources expose a public, filterable version_action_name atom attribute with unsafe_to_atom?: true by default.
The fix adds a coerce/2 to Ash.Type.Atom that never interns atoms — a comparison value is left as a string, since the type is stored and compared as a string. Setting the attribute from action input (cast_input/2, which still honors unsafe_to_atom?) is unchanged.
This issue affects ash: from 3.5.1 before 3.34.3.
- Database specific
{ "cna_assigner": "EEF", "cwe_ids": [ "CWE-770" ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/94xxx/CVE-2026-94201.json" }- References
-
- https://github.com
- https://osv.dev/vulnerability/EEF-CVE-2026-94201
- https://repo.hex.pm
- https://cna.erlef.org/cves/CVE-2026-94201.html
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/94xxx/CVE-2026-94201.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-94201
- https://github.com/ash-project/ash/commit/2970ba3bd5d36d6ad04c731ac87385375d457147
- https://github.com/ash-project/ash/commit/5282f3f513053628cdd1bf2236ea22d975d934d4
- https://github.com/ash-project/ash