# 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.

- **Severity:** Low 2.1 (`CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Sep 2026
- **Updated:** 1 Sep 2026
- **Also known as:** EEF-CVE-2026-82743, GHSA-33wq-x3q2-c92h

## 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 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-82743?

1 open source package ship an affected version, including ash.


| Package | Ecosystem | 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.

## Is CVE-2026-82743 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82743 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-82743 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82743 exists.

Affected packages and fixed versions:
- ash (Hex): affected from 2.19.0; fixed in 3.32.2

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-82743/ (Markdown: https://insights.sbomify.com/CVE-2026-82743/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-82743
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-82743
- OSV: https://osv.dev/vulnerability/CVE-2026-82743

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-82743/
Summaries are generated and may contain mistakes; the official description above is the record.