---
cve: "CVE-2026-94201"
severity: "HIGH"
cvss: 8.2
epss: "0.3%"
vendor: "ash-project"
kev: false
exploited: false
published: "2026-10-05 20:17:28"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-10-09T01:34:48+02:00"
---

# CVE-2026-94201

> 8.2 HIGH · 🧪 PoC

## Beschreibung

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.

## CNA-Record (Kanon, cvelistV5)

- CNA: **EEF**
- State: PUBLISHED
- Stand: 2026-10-05 19:19:51
- CNA-CVSS: **8.2** (`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`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **no**
  - Technical Impact: **partial**

## CVSS-Vektor

```
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
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 2970ba3bd5d36d6ad04c731ac87385375d457147 (Commit)
- 5282f3f513053628cdd1bf2236ea22d975d934d4 (Commit)

## Referenzen

- <https://cna.erlef.org/cves/CVE-2026-94201.html>
- <https://osv.dev/vulnerability/EEF-CVE-2026-94201>
- <https://github.com/ash-project/ash/commit/2970ba3bd5d36d6ad04c731ac87385375d457147>
- <https://github.com/ash-project/ash/commit/5282f3f513053628cdd1bf2236ea22d975d934d4>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-94201/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_