# CVE-2026-48817: Starlette: Arbitrary HTTP method dispatched to `HTTPEndpoint` attributes via `getattr`

> Attackers can invoke internal endpoint methods as HTTP handlers by using non-standard verbs, bypassing authorization checks in Starlette applications.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Jun 2026
- **Updated:** 18 Jun 2026
- **Also known as:** CLEANSTART-2026-OL54879, CLEANSTART-2026-RX49368, DEBIAN-CVE-2026-48817, ECHO-0b16-11b5-0d47, GHSA-x746-7m8f-x49c, MINI-2c76-v662-vqgx, MINI-6476-xc7c-p3mr, MINI-65cr-pw5x-j5rp, MINI-97cg-jc2c-fc4j, MINI-97m2-fch4-83rv, MINI-9cwc-53vx-36pm, MINI-cpfh-gph9-q5xr, MINI-gcjf-3jq4-p2rq, MINI-h6mq-f4cc-f283, MINI-m7r2-qc6f-x55w, MINI-mrm9-wq66-h279, MINI-pmqg-pj9r-c56c, MINI-pwf6-586g-fwhc, MINI-w5p6-629v-hvj3, MINI-wwjf-4599-xpwg, OESA-2026-3977, PYSEC-2026-2280, ROOT-APP-PYPI-CVE-2026-48817, UBUNTU-CVE-2026-48817

## What is CVE-2026-48817?

CVE-2026-48817 is a medium-severity missing authorization vulnerability in Kludex starlette, published on 17 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Starlette is a lightweight ASGI framework/toolkit. In versions 1.0.1 and below, when dispatching a request, HTTPEndpoint selects the handler by lowercasing the HTTP method and looking it up as an attribute with getattr, without restricting the lookup to a known set of HTTP verbs. When an HTTPEndpoint subclass is registered through Route(...) without an explicit methods= argument, the route does not constrain the method and every method reaches the endpoint. If a non-standard HTTP method whose lowercased name matches an attribute on the endpoint subclass reaches the endpoint, that attribute is invoked as if it were a request handler. An attacker can use this to reach methods that were never meant to be HTTP handlers, such as internal helpers, without the authorization checks applied by the intended public handler. An application (including Starlette-based frameworks like FastAPI) is affected if it registers an HTTPEndpoint subclass via Route(...) without explicitly setting methods=, and that subclass includes extra methods named like non-standard HTTP verbs that take one request argument and return a response. This issue has been fixed in version 1.1.0.

Weakness: CWE-470 (Use of Externally-Controlled Input to Select Classes or Code)

## Which versions are affected by CVE-2026-48817?

3 open source packages ship an affected version, including starlette. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `starlette` | PyPI | All versions | 1.1.0 |
| `starlette` | PyPI | All versions | 1.1.0 |
| `starlette` | PyPI | All versions | 1.1.0 |

Products: Encode Starlette.

## How do I fix CVE-2026-48817?

Upgrade starlette to 1.1.0 or later.

## Is CVE-2026-48817 being exploited?

There is no known exploitation of CVE-2026-48817 in the wild and no public exploit code.

## Other vulnerabilities in Kludex starlette

- [CVE-2026-48710](https://insights.sbomify.com/CVE-2026-48710/): Kludex Starlette HTTP Request/Response Smuggling (medium 6.5, exploited in the wild)
- [CVE-2026-54283](https://insights.sbomify.com/CVE-2026-54283/): Starlette: request.form() limits silently ignored for application/x-www-form-urlencoded enable DoS (high 7.5)
- [CVE-2026-48818](https://insights.sbomify.com/CVE-2026-48818/): Starlette: SSRF and NTLM credential theft via UNC paths in StaticFiles on Windows (high 7.5)
- [CVE-2023-29159](https://insights.sbomify.com/CVE-2023-29159/): Starlette has Path Traversal vulnerability in StaticFiles (high 7.5)
- [CVE-2023-30798](https://insights.sbomify.com/CVE-2023-30798/): MultipartParser DOS with too many fields or files in Starlette Framework (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-48817 and fix it if it is affected.

What it is: CVE-2026-48817 is a medium-severity missing authorization vulnerability in Kludex starlette, published on 17 Jun 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-2026-48817 in the wild and no public exploit code.

Affected packages and fixed versions:
- starlette (PyPI): affected all versions; fixed in 1.1.0
- starlette (PyPI): affected all versions; fixed in 1.1.0
- starlette (PyPI): affected all versions; fixed in 1.1.0

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-2026-48817/ (Markdown: https://insights.sbomify.com/CVE-2026-48817/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-48817
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-48817
- OSV: https://osv.dev/vulnerability/CVE-2026-48817

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-48817/
Summaries are generated and may contain mistakes; the official description above is the record.