CVE-2026-82724 Broken access control in AshPhoenix SubdomainHook via a nil tenant in handle_subdomain
Attackers can bypass tenant-scoped access controls in AshPhoenix SubdomainHook due to a nil tenant assignment during mount, potentially accessing unauthorized data.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-82724?
CVE-2026-82724 is a high-severity missing authorization vulnerability in ash-project ash_phoenix, published on 31 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-863
Which versions are affected by CVE-2026-82724?
1 open source package ship an affected version, including ash_phoenix.
| Package | Affected | Fixed in |
|---|---|---|
ash_phoenix Hex | From 2.1.26 | 2.3.25 |
How do I fix CVE-2026-82724?
Upgrade ash_phoenix to 2.3.25 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-82724 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82724 exists.
Sources
Also known as EEF-CVE-2026-82724, GHSA-39c8-xcwr-gqff.