CVE-2026-82743 Ash.Actions.Read.AsyncLimiter busy-spins a scheduler while awaiting slow async reads
A slow async read causes the Ash framework to busy-spin a scheduler thread, consuming full CPU and potentially 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-2026-82743?
CVE-2026-82743 is a low-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 a slow asynchronous read spin a scheduler thread at full CPU while the framework waits for it.
Ash.Actions.Read.AsyncLimiter.await_at_least_one/1 (lib/ash/actions/read/async_limiter.ex) waited for concurrent async read tasks by polling each with Task.yield(task, 0) in a tight loop rather than blocking. While every outstanding task is still running (a slow related-data load or calculation), the loop returns immediately and repeats, busy-spinning and holding a BEAM scheduler at full CPU for the whole duration of the slow read; concurrent slow reads tie up further schedulers. The fix waits with Task.yield_many (a non-blocking sweep followed by a blocking wait with timeout: :infinity), so the process sleeps until a task completes instead of spinning.
This issue affects ash: from 2.19.0 before 3.32.2.
Weakness: CWE-400
Which versions are affected by CVE-2026-82743?
1 open source package ship an affected version, including ash.
| Package | Affected | Fixed in |
|---|---|---|
ash Hex | From 2.19.0 | 3.32.2 |
How do I fix CVE-2026-82743?
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-2026-82743 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82743 exists.
Sources
Also known as EEF-CVE-2026-82743, GHSA-33wq-x3q2-c92h.