Broken access control in AshPhoenix SubdomainHook via a nil tenant in handle_subdomain
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-863.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| ash-project | ash_phoenix | 2.1.26 to before 2.3.25 | 2.3.25 | Patch available | CNA |
- ash_phoenix Vendorash-project Affected 2.1.26 to before 2.3.25 Fixed in 2.3.25 Patch available CNA
CPE names CNA · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:ash-project:ash_phoenix:*:*:*:*:*:*:*:* | — | — | — |
- cpe:2.3:a:ash-project:ash_phoenix:*:*:*:*:*:*:*:* Versions — — ·—
Remediation
- Fix · CNA ash_phoenix (ash-project) Fixed in 2.3.25
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
ash-project ash_phoenix 2.3.25
4 records Highest priority Priority HIGH 1 HIGH, 2 MEDIUM, 1 LOW
Other records, highest priority first
- TI-2026-57044 AshPhoenix get_subdomain maps a crafted or differently-cased Host header to an arbitrary tenantPriority MEDIUM 61
- TI-2026-57045 AshPhoenix Form.Auto leaks submitted params in an unknown _union_type error messagePriority MEDIUM 45
- TI-2026-57043 AshPhoenix FilterForm allows filtering across non-public relationships, disclosing private related dataPriority LOW 12
Timeline
- 2026-10-02 Threatist record created from CVE-2026-82724
References
More ash-project vulnerabilities
- TI-2026-56298 Query-complexity limit bypass via first/last pagination arguments in AshGraphql enables denial of service CVSS 4.0HIGH 8.7
- TI-2026-52572 Unbounded atom creation from client-supplied RPC field names in AshTypescript field formatter CVSS 4.0HIGH 8.7
- TI-2026-57010 Path traversal in AshAdmin file uploads via unsanitized client filename CVSS 4.0HIGH 8.3
- TI-2026-26840 Ash Framework: Ash.Type.Module.cast_input/2 atom exhaustion via unchecked Module.concat allows BEAM VM crash CVSS 4.0HIGH 8.2
- TI-2026-54252 EEx template evaluation of prompt content in AshAi enables remote code execution CVSS 4.0HIGH 8.9
- TI-2026-54208 Stored XSS in AshAdmin relationship typeahead via unescaped label_field content CVSS 4.0HIGH 8.4
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences