{"api_version":"1","generated_at":"2026-10-05T21:52:44+00:00","cve":"CVE-2026-94201","urls":{"html":"https://cve.report/CVE-2026-94201","api":"https://cve.report/api/cve/CVE-2026-94201.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-94201","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-94201"},"summary":{"title":"Filtering an :atom attribute with unsafe_to_atom? can exhaust the BEAM atom table in Ash","description":"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.\n\nFiltering 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.\n\nThe 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.\n\nThis issue affects ash: from 3.5.1 before 3.34.3.","state":"PUBLISHED","assigner":"EEF","published_at":"2026-10-05 20:17:28","updated_at":"2026-10-05 20:17:28"},"problem_types":["CWE-770","CWE-770 CWE-770 Allocation of Resources Without Limits or Throttling"],"metrics":[{"version":"4.0","source":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","type":"Secondary","score":"8.2","severity":"HIGH","vector":"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","data":{"version":"4.0","vectorString":"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","baseScore":8.2,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}},{"version":"4.0","source":"CNA","type":"CVSS","score":"8.2","severity":"HIGH","vector":"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","data":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":8.2,"baseSeverity":"HIGH","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"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","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"}}],"references":[{"url":"https://github.com/ash-project/ash/commit/2970ba3bd5d36d6ad04c731ac87385375d457147","name":"https://github.com/ash-project/ash/commit/2970ba3bd5d36d6ad04c731ac87385375d457147","refsource":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-94201","name":"https://osv.dev/vulnerability/EEF-CVE-2026-94201","refsource":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/ash-project/ash/commit/5282f3f513053628cdd1bf2236ea22d975d934d4","name":"https://github.com/ash-project/ash/commit/5282f3f513053628cdd1bf2236ea22d975d934d4","refsource":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://cna.erlef.org/cves/CVE-2026-94201.html","name":"https://cna.erlef.org/cves/CVE-2026-94201.html","refsource":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-94201","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-94201","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"ash-project","product":"ash","version":"affected 3.5.1 3.34.3 semver","platforms":[]},{"source":"CNA","vendor":"ash-project","product":"ash","version":"affected 2970ba3bd5d36d6ad04c731ac87385375d457147 5282f3f513053628cdd1bf2236ea22d975d934d4 git","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[{"source":"CNA","value":"Quinn Wilton","lang":"en"},{"source":"CNA","value":"Quinn Wilton","lang":"en"},{"source":"CNA","value":"Zach Daniel / Ash Project","lang":"en"},{"source":"CNA","value":"Jonatan Männchen / EEF","lang":"en"}],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:ash-project:ash:*:*:*:*:*:*:*:*"],"defaultStatus":"unaffected","modules":["'Elixir.Ash.Type.Atom'"],"packageName":"ash","packageURL":"pkg:hex/ash","product":"ash","programFiles":["lib/ash/type/atom.ex"],"programRoutines":[{"name":"'Elixir.Ash.Type.Atom':cast_value/2"}],"repo":"https://github.com/ash-project/ash","vendor":"ash-project","versions":[{"lessThan":"3.34.3","status":"affected","version":"3.5.1","versionType":"semver"}]},{"collectionURL":"https://github.com","cpes":["cpe:2.3:a:ash-project:ash:*:*:*:*:*:*:*:*"],"defaultStatus":"unaffected","modules":["'Elixir.Ash.Type.Atom'"],"packageName":"ash-project/ash","packageURL":"pkg:github/ash-project/ash","product":"ash","programFiles":["lib/ash/type/atom.ex"],"programRoutines":[{"name":"'Elixir.Ash.Type.Atom':cast_value/2"}],"repo":"https://github.com/ash-project/ash","vendor":"ash-project","versions":[{"lessThan":"5282f3f513053628cdd1bf2236ea22d975d934d4","status":"affected","version":"2970ba3bd5d36d6ad04c731ac87385375d457147","versionType":"git"}]}],"configurations":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>Reachable only when an application exposes a public, filterable <code>:atom</code> attribute declared with the <code>unsafe_to_atom?: true</code> constraint, and an actor can supply filter values for it (for example through AshGraphql, AshJsonApi, or <code>Ash.Query.filter_input/2</code>). AshPaperTrail's version resources ship such an attribute (<code>version_action_name</code>) by default.</p>"},{"base64":false,"type":"text/markdown","value":"Reachable only when an application exposes a public, filterable `:atom` attribute declared with the `unsafe_to_atom?: true` constraint, and an actor can supply filter values for it (for example through AshGraphql, AshJsonApi, or `Ash.Query.filter_input/2`). AshPaperTrail's version resources ship such an attribute (`version_action_name`) by default."}],"value":"Reachable only when an application exposes a public, filterable :atom attribute declared with the unsafe_to_atom?: true constraint, and an actor can supply filter values for it (for example through AshGraphql, AshJsonApi, or Ash.Query.filter_input/2). AshPaperTrail's version resources ship such an attribute (version_action_name) by default."}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:ash-project:ash:*:*:*:*:*:*:*:*","versionEndExcluding":"3.34.3","versionStartIncluding":"3.5.1","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"AND"}],"credits":[{"lang":"en","type":"finder","value":"Quinn Wilton"},{"lang":"en","type":"reporter","value":"Quinn Wilton"},{"lang":"en","type":"remediation developer","value":"Zach Daniel / Ash Project"},{"lang":"en","type":"coordinator","value":"Jonatan Männchen / EEF"}],"dateAssigned":"2026-10-04T15:49:18.000Z","descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>Ash stores <code>:atom</code>-typed attributes as strings and compares them as strings. When such an attribute is referenced in a filter, the comparison value is coerced through <code>Ash.Type.Atom</code>. Because the type defined no <code>coerce/2</code> callback, coercion fell back to the default (<code>cast_input/2</code>), which calls <code>String.to_atom/1</code> when the attribute is configured with the <code>unsafe_to_atom?: true</code> constraint.</p>\n<p>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 <code>:atom</code> attribute declared with <code>unsafe_to_atom?: true</code> can exhaust the atom table and crash the node (denial of service). AshPaperTrail is a notable example: its version resources expose a public, filterable <code>version_action_name</code> atom attribute with <code>unsafe_to_atom?: true</code> by default.</p>\n<p>The fix adds a <code>coerce/2</code> to <code>Ash.Type.Atom</code> 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 (<code>cast_input/2</code>, which still honors <code>unsafe_to_atom?</code>) is unchanged.</p>\n<p>This issue affects ash: from 3.5.1 before 3.34.3.</p>"},{"base64":false,"type":"text/markdown","value":"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.\n\nFiltering 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.\n\nThe 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.\n\nThis issue affects ash: from 3.5.1 before 3.34.3."}],"value":"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.\n\nFiltering 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.\n\nThe 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.\n\nThis issue affects ash: from 3.5.1 before 3.34.3."}],"impacts":[{"capecId":"CAPEC-130","descriptions":[{"lang":"en","value":"CAPEC-130 Excessive Allocation"}]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":8.2,"baseSeverity":"HIGH","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"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","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-770","description":"CWE-770 Allocation of Resources Without Limits or Throttling","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-10-05T19:19:51.326Z","orgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","shortName":"EEF"},"references":[{"name":"EEF CNA record for CVE-2026-94201","tags":["related","third-party-advisory"],"url":"https://cna.erlef.org/cves/CVE-2026-94201.html"},{"name":"OSV record EEF-CVE-2026-94201","tags":["related"],"url":"https://osv.dev/vulnerability/EEF-CVE-2026-94201"},{"name":"Introducing commit 2970ba3 in ash-project/ash","tags":["related"],"url":"https://github.com/ash-project/ash/commit/2970ba3bd5d36d6ad04c731ac87385375d457147"},{"name":"Fix commit 5282f3f in ash-project/ash","tags":["patch"],"url":"https://github.com/ash-project/ash/commit/5282f3f513053628cdd1bf2236ea22d975d934d4"}],"source":{"discovery":"EXTERNAL"},"title":"Filtering an :atom attribute with unsafe_to_atom? can exhaust the BEAM atom table in Ash"}},"cveMetadata":{"assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","assignerShortName":"EEF","cveId":"CVE-2026-94201","datePublished":"2026-10-05T19:19:51.326Z","dateReserved":"2026-09-24T09:15:02.216Z","dateUpdated":"2026-10-05T19:19:51.326Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-05 20:17:28","lastModifiedDate":"2026-10-05 20:17:28","problem_types":["CWE-770","CWE-770 CWE-770 Allocation of Resources Without Limits or Throttling"],"metrics":{"cvssMetricV40":[{"source":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","type":"Secondary","cvssData":{"version":"4.0","vectorString":"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","baseScore":8.2,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"94201","Ordinal":"1","Title":"Filtering an :atom attribute with unsafe_to_atom? can exhaust th","CVE":"CVE-2026-94201","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"94201","Ordinal":"1","NoteData":"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.\n\nFiltering 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.\n\nThe 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.\n\nThis issue affects ash: from 3.5.1 before 3.34.3.","Type":"Description","Title":"Filtering an :atom attribute with unsafe_to_atom? can exhaust th"}]}}}