---
cve: "CVE-2026-115927"
severity: "MEDIUM"
cvss: 5.3
epss: ""
vendor: "tornadoweb"
kev: false
exploited: false
published: "2026-10-26 20:17:52"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-10-29T17:18:33+01:00"
---

# CVE-2026-115927

> 5.3 MEDIUM · 🧪 PoC

## Beschreibung

Tornado is a Python web framework and asynchronous networking library. Prior to 6.6.0, Tornado decodes HTTP/1.1 chunked transfer encoding by processing body data that has already arrived without yielding to the event loop. A remote unauthenticated peer can send millions of one-byte chunks to monopolize the process event loop and stall every other connection served by that process, while lowering max_body_size only limits the duration of each request. For handlers that do not use @stream_request_body, retaining each chunk as a separate object can consume roughly twenty times the received body size, and SimpleAsyncHTTPClient has the same event-loop behavior when reading a response from a malicious server. This issue is fixed in version 6.6.0.

## CNA-Record (Kanon, cvelistV5)

- CNA: **GitHub_M**
- State: PUBLISHED
- Stand: 2026-10-27 14:18:44
- CNA-CVSS: **5.3** (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **yes**
  - Technical Impact: **partial**

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Keine | good |
| I Integrität | Keine | good |
| A Verfügbarkeit | Gering | warn |

## Schwachstellen-Klasse

- **CWE-400** — Uncontrolled Resource Consumption
  The product does not properly control the allocation and maintenance of a limited resource.
- **CWE-770** — Allocation of Resources Without Limits or Throttling
  The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

## Angriffsmuster (CAPEC)

- [CAPEC-147 — XML Ping of the Death](https://capec.mitre.org/data/definitions/147.html) _(Severity: Medium)_
- [CAPEC-227 — Sustained Client Engagement](https://capec.mitre.org/data/definitions/227.html)
- [CAPEC-492 — Regular Expression Exponential Blowup](https://capec.mitre.org/data/definitions/492.html)

## ATT&CK-Techniken

- [T1499 — Endpoint Denial of Service](https://attack.mitre.org/techniques/T1499/)

## Patch verfügbar (OSV)

- e2b0f452bbf0e554c64e9d9ee922341c1c634d95 (Commit)
- ceab33581489751a66fba8566ad6d5960d4b01c8 (Commit)

## Referenzen

- <https://github.com/tornadoweb/tornado/security/advisories/GHSA-r4j5-9xpp-3985>
- <https://github.com/tornadoweb/tornado/pull/3773>
- <https://github.com/tornadoweb/tornado/commit/ceab33581489751a66fba8566ad6d5960d4b01c8>
- <https://github.com/tornadoweb/tornado/releases/tag/v6.6.0>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-115927/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_