{"id":"CVE-2026-82724","state":"PUBLISHED","title":"Broken access control in AshPhoenix SubdomainHook via a nil tenant in handle_subdomain","description":"Incorrect 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\nAshPhoenix.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.","publishedAt":"2026-08-31T03:07:57.455Z","updatedAt":"2026-08-31T15:54:49.058Z","severity":{"score":7.6,"label":"High","version":"4.0","vector":"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","source":"EEF"},"assigner":"EEF","products":["ash-project ash_phoenix"],"affected":[{"vendor":"ash-project","product":"ash_phoenix","packageName":"ash_phoenix","packageURL":"pkg:hex/ash_phoenix","defaultStatus":"unaffected","versions":[{"version":"2.1.26","status":"affected","lessThan":"2.3.25","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:ash-project:ash_phoenix:*:*:*:*:*:*:*:*"],"modules":["'Elixir.AshPhoenix.LiveView.SubdomainHook'"],"programFiles":["lib/ash_phoenix/live_view/subdomain_hook.ex"],"programRoutines":[{"name":"'Elixir.AshPhoenix.LiveView.SubdomainHook':on_mount/4"}],"repo":"https://github.com/ash-project/ash_phoenix"},{"vendor":"ash-project","product":"ash_phoenix","packageName":"ash-project/ash_phoenix","packageURL":"pkg:github/ash-project/ash_phoenix","defaultStatus":"unaffected","versions":[{"version":"9a5ea4d377bc263de321d79574872a3dfc4fb541","status":"affected","lessThan":"b396e1aa5c6bdec39255f19cf938b539e6d28b71","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:ash-project:ash_phoenix:*:*:*:*:*:*:*:*"],"modules":["'Elixir.AshPhoenix.LiveView.SubdomainHook'"],"programFiles":["lib/ash_phoenix/live_view/subdomain_hook.ex"],"programRoutines":[{"name":"'Elixir.AshPhoenix.LiveView.SubdomainHook':on_mount/4"}],"repo":"https://github.com/ash-project/ash_phoenix"}],"references":["https://github.com/ash-project/ash_phoenix/security/advisories/GHSA-39c8-xcwr-gqff","https://cna.erlef.org/cves/CVE-2026-82724.html","https://osv.dev/vulnerability/EEF-CVE-2026-82724","https://github.com/ash-project/ash_phoenix/commit/b396e1aa5c6bdec39255f19cf938b539e6d28b71"],"weaknesses":["CWE-863"],"ingestedAt":"2026-10-29T20:13:15.269Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/82xxx/CVE-2026-82724.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-82724","state":"PUBLISHED","datePublished":"2026-08-31T03:07:57.455Z","dateUpdated":"2026-08-31T15:54:49.058Z","assignerShortName":"EEF","assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateReserved":"2026-08-31T00:59:08.960Z"},"containers":{"cna":{"title":"Broken access control in AshPhoenix SubdomainHook via a nil tenant in handle_subdomain","descriptions":[{"lang":"en","value":"Incorrect 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\nAshPhoenix.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."}],"affected":[{"vendor":"ash-project","product":"ash_phoenix","packageName":"ash_phoenix","packageURL":"pkg:hex/ash_phoenix","defaultStatus":"unaffected","versions":[{"version":"2.1.26","status":"affected","lessThan":"2.3.25","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:ash-project:ash_phoenix:*:*:*:*:*:*:*:*"],"modules":["'Elixir.AshPhoenix.LiveView.SubdomainHook'"],"programFiles":["lib/ash_phoenix/live_view/subdomain_hook.ex"],"programRoutines":[{"name":"'Elixir.AshPhoenix.LiveView.SubdomainHook':on_mount/4"}],"repo":"https://github.com/ash-project/ash_phoenix"},{"vendor":"ash-project","product":"ash_phoenix","packageName":"ash-project/ash_phoenix","packageURL":"pkg:github/ash-project/ash_phoenix","defaultStatus":"unaffected","versions":[{"version":"9a5ea4d377bc263de321d79574872a3dfc4fb541","status":"affected","lessThan":"b396e1aa5c6bdec39255f19cf938b539e6d28b71","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:ash-project:ash_phoenix:*:*:*:*:*:*:*:*"],"modules":["'Elixir.AshPhoenix.LiveView.SubdomainHook'"],"programFiles":["lib/ash_phoenix/live_view/subdomain_hook.ex"],"programRoutines":[{"name":"'Elixir.AshPhoenix.LiveView.SubdomainHook':on_mount/4"}],"repo":"https://github.com/ash-project/ash_phoenix"}],"references":[{"url":"https://github.com/ash-project/ash_phoenix/security/advisories/GHSA-39c8-xcwr-gqff","tags":["vendor-advisory","related"]},{"url":"https://cna.erlef.org/cves/CVE-2026-82724.html","tags":["related"]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-82724","tags":["related"]},{"url":"https://github.com/ash-project/ash_phoenix/commit/b396e1aa5c6bdec39255f19cf938b539e6d28b71","tags":["patch"]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":7.6,"baseSeverity":"HIGH","privilegesRequired":"LOW","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:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-863","description":"CWE-863 Incorrect Authorization","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"EEF","orgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateUpdated":"2026-08-31T03:07:57.455Z"},"configurations":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>The application uses <code>AshPhoenix.LiveView.SubdomainHook</code> with a <code>handle_subdomain</code> callback as a tenant-scoped authorization gate.</p>"},{"base64":false,"type":"text/markdown","value":"The application uses `AshPhoenix.LiveView.SubdomainHook` with a `handle_subdomain` callback as a tenant-scoped authorization gate."}],"value":"The application uses AshPhoenix.LiveView.SubdomainHook with a handle_subdomain callback as a tenant-scoped authorization gate."}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:ash-project:ash_phoenix:*:*:*:*:*:*:*:*","versionEndExcluding":"2.3.25","versionStartIncluding":"2.1.26","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"AND"}],"credits":[{"lang":"en","type":"finder","value":"Peter Ullrich"},{"lang":"en","type":"reporter","value":"Peter Ullrich"},{"lang":"en","type":"remediation developer","value":"Zach Daniel / Ash Project"},{"lang":"en","type":"coordinator","value":"Jonatan Männchen / EEF"}],"impacts":[{"capecId":"CAPEC-1","descriptions":[{"lang":"en","value":"CAPEC-1 Accessing Functionality Not Properly Constrained by ACLs"}]}],"source":{"discovery":"EXTERNAL"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/ash-project/ash_phoenix/security/advisories/GHSA-39c8-xcwr-gqff","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-31T15:53:54.952218Z","id":"CVE-2026-82724","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-31T15:54:49.058Z"}}]}}}