EEF-CVE-2026-82724 CVE-2026-82724 GHSA-39c8-xcwr-gqff
Broken access control in AshPhoenix SubdomainHook via a nil tenant in handle_subdomain
- Severity
- 0.0 / 10
- Unknown · CVSS 4.0
- Exploit chance (EPSS)
- 0.43%
- Chance of exploitation in the next 30 days. Higher than 37.02% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-863 Incorrect Authorization
- Fix
2.3.25- Upgrade ash_phoenix to this version or later
Description
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.
Configurations
The application uses AshPhoenix.LiveView.SubdomainHook with a handle_subdomain callback as a tenant-scoped authorization gate.
Affected versions
Hex
| Package | Vulnerable | Fixed in |
|---|---|---|
| ash_phoenix | >= 2.1.26, < 2.3.25 |
2.3.25 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
ash_phoenix Hex → 2.3.25
- mix
{:ash_phoenix, "~> 2.3.25"} # then: mix deps.update ash_phoenix
Severity breakdown
CVSS 4.0 0.0
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
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- Present
- Privileges required
- Low
- User interaction
- None
- Confidentiality (vulnerable system)
- High
- Integrity (vulnerable system)
- High
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
Weakness
CWE-863: Incorrect Authorization
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
How to prevent it
- Architecture and Design: Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Architecture and Design: Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor [REF-7].
- Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
- Architecture and Design: For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page. One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.
- System Configuration, Installation: Use the access control capabilities of your operating system and server environment and define your access control lists accordingly. Use a "default deny" policy when defining these ACLs.
References
Advisories
Fixes and patches
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| EEF-CVE-2026-82725 AshPhoenix FilterForm allows filtering across non-public relationships, disclosing private related data | Not rated yet | Also affects ash_phoenix |
| EEF-CVE-2026-82726 AshPhoenix get_subdomain maps a crafted or differently-cased Host header to an arbitrary tenant | Not rated yet | Also affects ash_phoenix |
| EEF-CVE-2026-82727 AshPhoenix Form.Auto leaks submitted params in an unknown _union_type error message | Not rated yet | Also affects ash_phoenix |
| GHSA-9v7c-q64q-vv33 Nuxt: Dot segments in the request path bypass `server/middleware` path checks and server route rules on page routes | Medium | Same weakness, CWE-863 |
| EEF-CVE-2026-115627 AshPostgres ignores attribute multitenancy on the join resource when loading many_to_many and through relationships, returning records related through other tenants' rows | Not rated yet | Same weakness, CWE-863 |
| EEF-CVE-2026-115635 AshPostgres returns another tenant's record for a skipped upsert when return_skipped_upsert? is set | Not rated yet | Same weakness, CWE-863 |
| EEF-CVE-2026-114214 Loading a through relationship with a limit of 1 in Ash ignores the through path and returns unrelated destination records | Not rated yet | Same weakness, CWE-863 |
| GHSA-xp3q-r38w-vgqm SiYuan: The publish filter for local storage returns the administrator's entire storage map with only three keys sanitized | Medium | Same weakness, CWE-863 |
Credits: Jonatan Männchen / EEF, Peter Ullrich, Zach Daniel / Ash Project
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