{"id":"CVE-2026-81853","aliases":["EEF-CVE-2026-81853","EUVD-2026-68330","GHSA-jxr8-hpv2-qp38"],"status":"published","title":"AshAdmin composite primary key decoding accepts arbitrary fields, enabling a secret-attribute oracle","description":"Authorization Bypass Through User-Controlled Key vulnerability in ash-project ash_admin turns a record-lookup URL into an equality oracle over sensitive attributes.\n\nAshAdmin.Helpers.decode_primary_key/2 decodes the composite-primary-key form (Base64 plus ETF) and returns the decoded map verbatim as the lookup filter, without checking that its keys are the resource's primary-key fields. The deserialization guards bound size, block new atoms and funs, and reject nested expressions, but none restricts which fields come back, and :safe still allows any already-interned attribute name. An attacker can therefore encode %{api_token: \"guess\"} and have it spliced into the lookup filter, brute-forcing a sensitive attribute value (API token, reset token) one equality guess at a time; Map.to_list/1 also accepts structs, yielding a bogus __struct__ key. The fix rejects any decoded key that is not a real primary-key field.\n\nThis issue affects ash_admin: from 0.1.0 before 1.3.1.","severity":{"version":"4.0","score":2.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"low","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00449,"percentile":0.39493,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-639"],"published":"2026-08-31T02:31:29Z","modified":"2026-10-28T02:31:13Z","fixes":[{"ecosystem":"Hex","package":"ash_admin","fixed_in":["1.3.1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Hex","package":"ash_admin","ranges":[{"type":"SEMVER","events":[{"introduced":"0.1.0"},{"fixed":"1.3.1"}]}],"versions":["0.1.0","0.1.2","0.1.3","0.1.5","0.1.6","0.10.0","0.10.1","0.10.10","0.10.10-rc.0","0.10.10-rc.1","0.10.11","0.10.12","0.10.2","0.10.3","0.10.4","0.10.5","0.10.6","0.10.7","0.10.8","0.10.9","0.11.0","0.11.1","0.11.10","0.11.11","0.11.2","0.11.3","0.11.4","0.11.5","0.11.6","0.11.7","0.11.8","0.11.9","0.12.0","0.12.1","0.12.2","0.12.3","0.12.4","0.12.5","0.12.6","0.13.0","0.13.1","0.13.10","0.13.11","0.13.12","0.13.13","0.13.14","0.13.15","0.13.16","0.13.17","0.13.18","0.13.19","0.13.2","0.13.20","0.13.21","0.13.22","0.13.23","0.13.24","0.13.25","0.13.26","0.13.3","0.13.4","0.13.5","0.13.6","0.13.7","0.13.8","0.13.9","0.14.0","0.2.1","0.2.10","0.2.11","0.2.12","0.2.13","0.2.14","0.2.15","0.2.16-rc.0","0.2.16-rc.1","0.2.17","0.2.18","0.2.19","0.2.20","0.2.21","0.2.22","0.2.3","0.2.4","0.2.5","0.2.6","0.2.7","0.2.8","0.2.9","0.3.0-rc.0","0.4.0","0.4.2","0.4.4","0.4.5-rc.0","0.5.0","0.5.1-rc.0","0.5.2","0.6.0-rc.0","0.6.0-rc.1","0.6.0-rc.2","0.6.1","0.6.2","0.7.0","0.7.1","0.8.0","0.8.1","0.9.0","0.9.1","0.9.2","0.9.3","0.9.4","0.9.5","0.9.6","0.9.7","0.9.8","1.0.0-rc.0","1.1.0","1.2.0","1.3.0"]}],"products":[{"vendor":"ash-project","product":"ash_admin"}],"references":[{"url":"https://github.com/ash-project/ash_admin/security/advisories/GHSA-jxr8-hpv2-qp38","tags":["vendor-advisory","related","exploit","advisory"]},{"url":"https://cna.erlef.org/cves/CVE-2026-81853.html","tags":["related","web"]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-81853","tags":["related","web"]},{"url":"https://github.com/ash-project/ash_admin/commit/3c3e905d47f1155dcc1ca3fb347348b05a66065a","tags":["patch","fix"]},{"url":"https://github.com","tags":["web"]},{"url":"https://repo.hex.pm","tags":["web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81853.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-81853","tags":["advisory"]},{"url":"https://github.com/ash-project/ash_admin","tags":["package"]},{"url":"https://hex.pm/packages/ash_admin","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-81853","title":"AshAdmin composite primary key decoding accepts arbitrary fields, enabling a secret-attribute oracle","description":"Authorization Bypass Through User-Controlled Key vulnerability in ash-project ash_admin turns a record-lookup URL into an equality oracle over sensitive attributes.\n\nAshAdmin.Helpers.decode_primary_key/2 decodes the composite-primary-key form (Base64 plus ETF) and returns the decoded map verbatim as the lookup filter, without checking that its keys are the resource's primary-key fields. The deserialization guards bound size, block new atoms and funs, and reject nested expressions, but none restricts which fields come back, and :safe still allows any already-interned attribute name. An attacker can therefore encode %{api_token: \"guess\"} and have it spliced into the lookup filter, brute-forcing a sensitive attribute value (API token, reset token) one equality guess at a time; Map.to_list/1 also accepts structs, yielding a bogus __struct__ key. The fix rejects any decoded key that is not a real primary-key field.\n\nThis issue affects ash_admin: from 0.1.0 before 1.3.1.","status":"published","published":"2026-08-31T02:31:29.547Z","modified":"2026-08-31T15:58:40.226Z","cvss":[{"version":"4.0","score":2.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"low","assessor":"cna"}],"cwes":["CWE-639"],"updated_at":"2026-11-02T13:36:18.075535Z"}],"euvd":[{"id":"EUVD-2026-68330","description":"Authorization Bypass Through User-Controlled Key vulnerability in ash-project ash_admin turns a record-lookup URL into an equality oracle over sensitive attributes.\n\nAshAdmin.Helpers.decode_primary_key/2 decodes the composite-primary-key form (Base64 plus ETF) and returns the decoded map verbatim as the lookup filter, without checking that its keys are the resource's primary-key fields. The deserialization guards bound size, block new atoms and funs, and reject nested expressions, but none restricts which fields come back, and :safe still allows any already-interned attribute name. An attacker can therefore encode %{api_token: \"guess\"} and have it spliced into the lookup filter, brute-forcing a sensitive attribute value (API token, reset token) one equality guess at a time; Map.to_list/1 also accepts structs, yielding a bogus __struct__ key. The fix rejects any decoded key that is not a real primary-key field.\n\nThis issue affects ash_admin: from 0.1.0 before 1.3.1.","status":"published","published":"2026-08-31T02:31:29Z","modified":"2026-08-31T15:58:40Z","cvss":[{"version":"4.0","score":2.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"low"}],"updated_at":"2026-11-02T18:01:20.704822Z"}],"nvd":[{"id":"CVE-2026-81853","description":"Authorization Bypass Through User-Controlled Key vulnerability in ash-project ash_admin turns a record-lookup URL into an equality oracle over sensitive attributes.\n\nAshAdmin.Helpers.decode_primary_key/2 decodes the composite-primary-key form (Base64 plus ETF) and returns the decoded map verbatim as the lookup filter, without checking that its keys are the resource's primary-key fields. The deserialization guards bound size, block new atoms and funs, and reject nested expressions, but none restricts which fields come back, and :safe still allows any already-interned attribute name. An attacker can therefore encode %{api_token: \"guess\"} and have it spliced into the lookup filter, brute-forcing a sensitive attribute value (API token, reset token) one equality guess at a time; Map.to_list/1 also accepts structs, yielding a bogus __struct__ key. The fix rejects any decoded key that is not a real primary-key field.\n\nThis issue affects ash_admin: from 0.1.0 before 1.3.1.","status":"published","published":"2026-08-31T03:16:42.67Z","modified":"2026-09-01T21:15:00.147Z","cvss":[{"version":"4.0","score":2.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/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","level":"low","assessor":"secondary"}],"cwes":["CWE-639"],"updated_at":"2026-11-02T14:12:42.691315Z"}],"osv":[{"id":"CVE-2026-81853","title":"AshAdmin composite primary key decoding accepts arbitrary fields, enabling a secret-attribute oracle","description":"Authorization Bypass Through User-Controlled Key vulnerability in ash-project ash_admin turns a record-lookup URL into an equality oracle over sensitive attributes.\n\nAshAdmin.Helpers.decode_primary_key/2 decodes the composite-primary-key form (Base64 plus ETF) and returns the decoded map verbatim as the lookup filter, without checking that its keys are the resource's primary-key fields. The deserialization guards bound size, block new atoms and funs, and reject nested expressions, but none restricts which fields come back, and :safe still allows any already-interned attribute name. An attacker can therefore encode %{api_token: \"guess\"} and have it spliced into the lookup filter, brute-forcing a sensitive attribute value (API token, reset token) one equality guess at a time; Map.to_list/1 also accepts structs, yielding a bogus __struct__ key. The fix rejects any decoded key that is not a real primary-key field.\n\nThis issue affects ash_admin: from 0.1.0 before 1.3.1.","status":"published","published":"2026-08-31T02:31:29.547Z","modified":"2026-10-28T02:31:13.907029993Z","cvss":[{"version":"4.0","score":2.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"low"}],"cwes":["CWE-639"],"updated_at":"2026-11-02T15:45:18.131258Z"},{"id":"EEF-CVE-2026-81853","title":"AshAdmin composite primary key decoding accepts arbitrary fields, enabling a secret-attribute oracle","description":"## Summary\n\nAuthorization Bypass Through User-Controlled Key vulnerability in ash-project ash_admin turns a record-lookup URL into an equality oracle over sensitive attributes.\n\n`AshAdmin.Helpers.decode_primary_key/2` decodes the composite-primary-key form (Base64 plus ETF) and returns the decoded map verbatim as the lookup filter, without checking that its keys are the resource's primary-key fields. The deserialization guards bound size, block new atoms and funs, and reject nested expressions, but none restricts which fields come back, and `:safe` still allows any already-interned attribute name. An attacker can therefore encode `%{api_token: \"guess\"}` and have it spliced into the lookup filter, brute-forcing a sensitive attribute value (API token, reset token) one equality guess at a time; `Map.to_list/1` also accepts structs, yielding a bogus `__struct__` key. The fix rejects any decoded key that is not a real primary-key field.\n\nThis issue affects ash_admin: from 0.1.0 before 1.3.1.\n\n## Configurations\n\nThe resource has a composite primary key, and the deployment relies on AshAdmin's authorization (a custom actor plug and policies) so that reading otherwise-restricted attribute values crosses a boundary.","status":"published","published":"2026-08-31T02:31:29.547Z","modified":"2026-09-08T03:30:04.105476988Z","cvss":[{"version":"4.0","score":2.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"low"}],"cwes":["CWE-639"],"updated_at":"2026-11-02T15:46:33.520522Z"}]}}