# CVE-2026-35526: Strawberry GraphQL affected by a Denial of Service via unbounded WebSocket subscriptions

> An unauthenticated attacker can cause server crashes or degradation by flooding WebSocket subscriptions in Strawberry GraphQL, requiring an upgrade to fix.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 Apr 2026
- **Updated:** 8 Apr 2026
- **Also known as:** GHSA-hv3w-m4g2-5x77, PYSEC-2026-134, ROOT-APP-PYPI-CVE-2026-35526

## What is CVE-2026-35526?

CVE-2026-35526 is a high-severity denial of service vulnerability in strawberry-graphql strawberry, published on 7 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Strawberry GraphQL is a library for creating GraphQL APIs. Prior to 0.312.3, Strawberry GraphQL's WebSocket subscription handlers for both the graphql-transport-ws and legacy graphql-ws protocols allocate an asyncio.Task and associated Operation object for every incoming subscribe message without enforcing any limit on the number of active subscriptions per connection. An unauthenticated attacker can open a single WebSocket connection, send connection_init, and then flood subscribe messages with unique IDs. Each message unconditionally spawns a new asyncio.Task and async generator, causing linear memory growth and event loop saturation. This leads to server degradation or an OOM crash. This vulnerability is fixed in 0.312.3.

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

## Which versions are affected by CVE-2026-35526?

3 open source packages ship an affected version, including strawberry-graphql. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `strawberry-graphql` | PyPI | All versions | 0.312.3 |
| `strawberry-graphql` | PyPI | All versions | 0.312.3 |
| `strawberry-graphql` | PyPI | All versions | 0.312.3 |

Products: Strawberry Strawberry Graphql.

## How do I fix CVE-2026-35526?

Upgrade strawberry-graphql to 0.312.3 or later.

## Is CVE-2026-35526 being exploited?

There is no known exploitation of CVE-2026-35526 in the wild and no public exploit code.

## Other vulnerabilities in strawberry-graphql strawberry

- [CVE-2026-35523](https://insights.sbomify.com/CVE-2026-35523/): Authentication bypass in strawberry-graphql via legacy graphql-ws WebSocket subprotocol (high 7.5)
- [CVE-2026-47706](https://insights.sbomify.com/CVE-2026-47706/): Strawberry GraphQL has a Circular Fragment Reference DOS (medium 5.3)
- [CVE-2026-47707](https://insights.sbomify.com/CVE-2026-47707/): Strawberry GraphQL's Bypass of MaxAliasesLimiter via Fragment Spreads leading to GraphQL Alias Amplification (medium 5.3)
- [CVE-2026-45739](https://insights.sbomify.com/CVE-2026-45739/): Strawberry GraphQL: Default GraphiQL may expose HTTP headers in URLs (low 3.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-35526 and fix it if it is affected.

What it is: CVE-2026-35526 is a high-severity denial of service vulnerability in strawberry-graphql strawberry, published on 7 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-35526 in the wild and no public exploit code.

Affected packages and fixed versions:
- strawberry-graphql (PyPI): affected all versions; fixed in 0.312.3
- strawberry-graphql (PyPI): affected all versions; fixed in 0.312.3
- strawberry-graphql (PyPI): affected all versions; fixed in 0.312.3

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-2026-35526/ (Markdown: https://insights.sbomify.com/CVE-2026-35526/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-35526
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-35526
- OSV: https://osv.dev/vulnerability/CVE-2026-35526

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-35526/
Summaries are generated and may contain mistakes; the official description above is the record.