CVE-2026-82742 Ash.Filter.Runtime materializes a combinatorial cross-product over to-many relationships, exhausting memory
Attackers can exhaust memory by triggering combinatorial expansion of to-many relationships in Ash.Filter.Runtime, causing denial of service.
- 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-2026-82742?
CVE-2026-82742 is a medium-severity denial of service 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
Uncontrolled Resource Consumption vulnerability in ash-project ash lets an attacker exhaust node memory by matching a filter that spans multiple to-many relationships in memory.
Ash.Filter.Runtime matches a filter against an in-memory record by first expanding the record into combinations of its related rows. flatten_relationships/2 (lib/ash/filter/runtime.ex) eagerly built the full Cartesian product across the filter's to-many relationship paths, so a record with K to-many relationships of M rows each materialized on the order of M^K scenarios before any predicate was checked. A filter or dataset that reaches several sizeable to-many relationships therefore allocates memory combinatorially and can exhaust the node. The fix streams the expansion lazily and short-circuits on the first matching scenario, bounding the work.
This issue affects ash: from 1.29.0-rc0 before 3.32.2.
Weakness: CWE-400
Which versions are affected by CVE-2026-82742?
1 open source package ship an affected version, including ash.
| Package | Affected | Fixed in |
|---|---|---|
ash Hex | From 1.29.0-rc0 | 3.32.2 |
How do I fix CVE-2026-82742?
Upgrade ash to 3.32.2 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-82742 being exploited?
There is no known exploitation of CVE-2026-82742 in the wild and no public exploit code.
Sources
Also known as EEF-CVE-2026-82742, GHSA-mgwj-c69v-6f83.