CVE-2026-82747 Ash.Policy.Authorizer returns records denied by a runtime read policy to any actor
Attackers can access records denied by runtime read policies due to a logic error in Ash.Policy.Authorizer, exposing sensitive data to unauthorized actors.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-82747?
CVE-2026-82747 is a medium-severity missing authorization vulnerability in ash-project ash, published on 1 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Incorrect Authorization vulnerability in ash-project ash returns records that a runtime read policy denies to any actor.
When a resource has an access_type :runtime read policy (a check evaluated per record rather than compiled to a filter), Ash.Policy.Authorizer decides each record in check_result/1 (lib/ash/policy/authorizer/authorizer.ex) by discarding impossible policy scenarios and inspecting what remains. When every scenario for a record was impossible, meaning no policy can authorize it and it must be forbidden, the empty-scenario branch instead kept the record ({[record | data], authorizer, any_forbidden?}) and returned it as authorized. As a result, records the runtime read policy denies are returned to any actor. The fix forbids a record whose scenarios are all impossible.
This issue affects ash: from 3.4.44 before 3.32.2.
Weakness: CWE-863
Which versions are affected by CVE-2026-82747?
1 open source package ship an affected version, including ash.
| Package | Affected | Fixed in |
|---|---|---|
ash Hex | From 3.4.44 | 3.32.2 |
How do I fix CVE-2026-82747?
Upgrade ash to 3.32.2 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-82747 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82747 exists.
Sources
Also known as EEF-CVE-2026-82747, GHSA-4259-gvr2-4xhq.