# CVE-2026-81636: Query-complexity limit bypass via first/last pagination arguments in AshGraphql enables denial of service

> Unauthenticated attackers can bypass query complexity limits in AshGraphql to force unbounded database reads, causing denial of service.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/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:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Aug 2026
- **Updated:** 31 Aug 2026
- **Also known as:** EEF-CVE-2026-81636, GHSA-mwc4-r9fc-h6mg

## What is CVE-2026-81636?

CVE-2026-81636 is a high-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

Allocation of Resources Without Limits or Throttling vulnerability in ash-project ash_graphql allows an unauthenticated client to bypass the configured GraphQL query-complexity limit and force an unbounded database read.

AshGraphql.Graphql.Resolver.query_complexity/3 multiplies child complexity by the requested page size only when the argument map contains :limit (offset pagination). Relay connections and keyset pagination use first and last, which never match that clause and fall through to the catch-all that returns child_complexity + 1. A nested relay query such as posts(first: 500) { edges { node { comments(first: 500) { ... } } } } therefore scores as trivially cheap while materializing the full fan-out, passing an Absinthe max_complexity cap that rejects the equivalent limit-based query. The fix adds first and last clauses clamped to the action's page size.

This issue affects ash_graphql: from 0.16.23 before 1.11.0.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-81636?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `ash_graphql` | Hex | From 0.16.23 | 1.11.0 |

## How do I fix CVE-2026-81636?

Upgrade ash_graphql to 1.11.0 or later.

## Is CVE-2026-81636 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-81636 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-81636 and fix it if it is affected.

What it is: CVE-2026-81636 is a high-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-2026-81636 exists.

Affected packages and fixed versions:
- ash_graphql (Hex): affected from 0.16.23; 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-2026-81636/ (Markdown: https://insights.sbomify.com/CVE-2026-81636/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-81636
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-81636
- OSV: https://osv.dev/vulnerability/CVE-2026-81636

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-81636/
Summaries are generated and may contain mistakes; the official description above is the record.