# CVE-2026-69659: Memory exhaustion via unbounded deserialization of keyset pagination cursors in Ash.Page.Keyset

> Attackers can cause denial of service by sending crafted keyset pagination cursors that trigger memory exhaustion via unsafe deserialization.

- **Severity:** Medium 5.9 (`CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/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:** 9 Aug 2026
- **Updated:** 10 Aug 2026
- **Also known as:** EEF-CVE-2026-69659, GHSA-j35q-v8h8-7mwq

## What is CVE-2026-69659?

CVE-2026-69659 is a medium-severity unsafe deserialization vulnerability in ash-project ash, published on 9 Aug 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 allows an attacker to exhaust the memory of the node via a crafted keyset pagination cursor.

Read actions with keyset pagination deserialize the client-supplied page[:after] or page[:before] cursor in decode_values/2 in lib/ash/page/keyset.ex, which base64-decodes the value and passes it to :erlang.binary_to_term/2 without bounding its size. The Erlang external term format supports zlib-compressed payloads, which the decoder inflates transparently, so a cursor of a few kilobytes can allocate tens of megabytes of heap in a single call. Ash itself only ever encodes cursors uncompressed, so the decoder accepts a term shape its encoder never produces. Concurrent requests aggregate these allocations and can terminate the node.

This issue affects ash: from 1.17.0 before 3.31.1.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2026-69659?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `ash` | Hex | From 1.17.0 | 3.31.1 |

Products: Ash-Hq Ash Framework.

## How do I fix CVE-2026-69659?

Upgrade ash to 3.31.1 or later.

## Is CVE-2026-69659 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-69659 exists.

## Other vulnerabilities in ash-project ash

- [CVE-2026-34593](https://insights.sbomify.com/CVE-2026-34593/): Ash Framework: Ash.Type.Module.cast_input/2 atom exhaustion via unchecked Module.concat allows BEAM VM crash (high 8.2)
- [CVE-2026-67579](https://insights.sbomify.com/CVE-2026-67579/): Filter expression injection via forged keyset pagination cursor in Ash (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-69659 and fix it if it is affected.

What it is: CVE-2026-69659 is a medium-severity unsafe deserialization vulnerability in ash-project ash, published on 9 Aug 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-2026-69659 exists.

Affected packages and fixed versions:
- ash (Hex): affected from 1.17.0; fixed in 3.31.1

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-2026-69659/ (Markdown: https://insights.sbomify.com/CVE-2026-69659/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-69659
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-69659
- OSV: https://osv.dev/vulnerability/CVE-2026-69659

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-69659/
Summaries are generated and may contain mistakes; the official description above is the record.