{"id":"EEF-CVE-2026-82724","summary":"Broken access control in AshPhoenix SubdomainHook via a nil tenant in handle_subdomain","details":"## Summary\n\nIncorrect Authorization vulnerability in ash-project ash_phoenix invokes the `SubdomainHook` authorization callback with a `nil` tenant, so tenant-scoped access checks never see the tenant they are meant to enforce.\n\n`AshPhoenix.LiveView.SubdomainHook.on_mount/4` attached a `handle_params` hook to assign the tenant and then immediately called `handle_subdomain` in the same `on_mount`. The tenant assign is only written when LiveView later runs `handle_params`, strictly after `on_mount` returns, so `handle_subdomain` read an unset assign and ran as `apply(m, f, [socket, nil | a])`. A consumer gate that halts when the user does not belong to the tenant instead evaluated `nil`, either crashing or taking a permissive branch, and it was never re-run once the real subdomain was assigned or on later navigations. The fix runs `handle_subdomain` inside the `handle_params` hook with the real tenant on every navigation.\n\nThis issue affects ash_phoenix: from 2.1.26 before 2.3.25.\n\n## Configurations\n\nThe application uses `AshPhoenix.LiveView.SubdomainHook` with a `handle_subdomain` callback as a tenant-scoped authorization gate.","aliases":["CVE-2026-82724","GHSA-39c8-xcwr-gqff"],"modified":"2026-09-08T03:45:09.966070734Z","published":"2026-08-31T03:07:57.455Z","database_specific":{"cwe_ids":["CWE-863"],"capec_ids":["CAPEC-1"],"cpe_ids":["cpe:2.3:a:ash-project:ash_phoenix:*:*:*:*:*:*:*:*"]},"references":[{"type":"ADVISORY","url":"https://github.com/ash-project/ash_phoenix/security/advisories/GHSA-39c8-xcwr-gqff"},{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-82724.html"},{"type":"FIX","url":"https://github.com/ash-project/ash_phoenix/commit/b396e1aa5c6bdec39255f19cf938b539e6d28b71"},{"type":"PACKAGE","url":"https://hex.pm/packages/ash_phoenix"}],"affected":[{"package":{"name":"ash_phoenix","ecosystem":"Hex","purl":"pkg:hex/ash_phoenix"},"ranges":[{"type":"SEMVER","events":[{"introduced":"2.1.26"},{"fixed":"2.3.25"}]}],"versions":["2.1.26","2.2.0","2.3.0","2.3.1","2.3.10","2.3.11","2.3.12","2.3.13","2.3.14","2.3.15","2.3.16","2.3.17","2.3.18","2.3.19","2.3.2","2.3.20","2.3.21","2.3.22","2.3.23","2.3.24","2.3.3","2.3.4","2.3.5","2.3.6","2.3.7","2.3.8","2.3.9"],"database_specific":{"source":"https://cna.erlef.org/osv/EEF-CVE-2026-82724.json"}},{"ranges":[{"type":"GIT","repo":"https://github.com/ash-project/ash_phoenix","events":[{"introduced":"9a5ea4d377bc263de321d79574872a3dfc4fb541"},{"fixed":"b396e1aa5c6bdec39255f19cf938b539e6d28b71"}]}],"versions":["v2.3.24","v2.3.23","v2.3.22","v2.3.21","v2.3.20","v2.3.19","v2.3.18","v2.3.17","v2.3.10","v2.3.16","v2.3.15","v2.3.14","v2.3.13","v2.3.12","v2.3.11","v2.3.9","v2.3.8","v2.3.7","v2.3.6","v2.3.5","v2.3.4","v2.3.3","v2.3.2","v2.3.1","v2.3.0","v2.2.0","v2.1.26"],"database_specific":{"source":"https://cna.erlef.org/osv/EEF-CVE-2026-82724.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"}],"credits":[{"name":"Peter Ullrich","type":"FINDER"},{"name":"Peter Ullrich","type":"REPORTER"},{"name":"Zach Daniel / Ash Project","type":"REMEDIATION_DEVELOPER"},{"name":"Jonatan Männchen / EEF","type":"COORDINATOR"}]}