# CVE-2026-81633: Unhandled KeyError in AshGraphql relay node resolution crashes queries via an unknown type segment

> An unauthenticated attacker can crash GraphQL queries and potentially expose stack traces by sending a malformed relay node ID with an unknown type segment.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Aug 2026
- **Updated:** 31 Aug 2026
- **Also known as:** EEF-CVE-2026-81633, GHSA-mrgv-g7gf-r96h

## What is CVE-2026-81633?

CVE-2026-81633 is a medium-severity denial of service vulnerability in ash-project ash_graphql, published on 30 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Improper Input Validation vulnerability in ash-project ash_graphql allows an unauthenticated client to crash a relay node(id: ...) query with an unhandled KeyError.

AshGraphql.Graphql.Resolver.resolve_node/2 decodes the client-supplied global ID with decode_relay_id/1, which only base64-decodes the string and splits it on : without validating the type segment. The decoded type is passed straight to Map.fetch!(type_to_domain_and_resource_map, type). Because fetch! raises on a missing key, a relay ID whose type segment is a valid atom that is not a relay-exposed type aborts the resolver before its resolve/2 clauses and their rescue handlers run, so the error never becomes a GraphQL error and may expose a stacktrace. Common resource names are easy to guess. The fix uses Map.fetch/2 and returns an Invalid node id error for unknown types.

This issue affects ash_graphql: from 0.27.0 before 1.11.0.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2026-81633?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `ash_graphql` | Hex | From 0.27.0 | 1.11.0 |

## How do I fix CVE-2026-81633?

Upgrade ash_graphql to 1.11.0 or later.

## Is CVE-2026-81633 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-81633 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-81633 and fix it if it is affected.

What it is: CVE-2026-81633 is a medium-severity denial of service vulnerability in ash-project ash_graphql, published on 30 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-81633 exists.

Affected packages and fixed versions:
- ash_graphql (Hex): affected from 0.27.0; fixed in 1.11.0

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-2026-81633/ (Markdown: https://insights.sbomify.com/CVE-2026-81633/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-81633
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-81633
- OSV: https://osv.dev/vulnerability/CVE-2026-81633

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-81633/
Summaries are generated and may contain mistakes; the official description above is the record.