Broken access control in AshPhoenix SubdomainHook via a nil tenant in handle_subdomain (CVE-2026-82724) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-82724

Broken access control in AshPhoenix SubdomainHook via a nil tenant in handle_subdomain

Answer in brief

CVE-2026-82724 records a Unknown severity vulnerability in Broken access control in AshPhoenix SubdomainHook via a nil tenant in handle_subdomain. The current sources do not mark it as known exploited. The current feed maps ash-project/ash_phoenix (generic), ash-project/ash_phoenix (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 31, 2026Updated Aug 31, 2026Source checked Aug 31, 2026First seen by HOL Aug 31, 2026Material review Aug 31, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps ash-project/ash_phoenix (generic), ash-project/ash_phoenix (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
ash-project/ash_phoenixgeneric	>=2.1.26 <2.3.25	2.3.25
ash-project/ash_phoenixgeneric	>=9a5ea4d377bc263de321d79574872a3dfc4fb541 <b396e1aa5c6bdec39255f19cf938b539e6d28b71	b396e1aa5c6bdec39255f19cf938b539e6d28b71

Recommended response

Check inventory. Check lockfiles and deployed manifests for ash-project/ash_phoenix, ash-project/ash_phoenix.
Review the reported fix. Update ash-project/ash_phoenix to 2.3.25; ash-project/ash_phoenix to b396e1aa5c6bdec39255f19cf938b539e6d28b71 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 31, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 31, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 31, 2026

Sources and claim methodology

Upstream source 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. 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. This issue affects ash_phoenix: from 2.1.26 before 2.3.25.

Quoted source text, attributed separately from HOL analysis.