Findings

CVE-2026-31958

Tornado is a Python web framework and asynchronous networking library.

Published Mar 11, 2026 · updated Jun 17, 2026 · tornadoweb tornado

Tornado is a Python web framework and asynchronous networking library. In versions of Tornado prior to 6.5.5, the only limit on the number of parts in multipart/form-data is the max_body_size setting (default 100MB). Since parsing occurs synchronously on the main thread, this creates the possibility of denial-of-service due to the cost of parsing very large multipart bodies with many parts. This vulnerability is fixed in 6.5.5.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Mar 11, 2026 · NIST NVD

    Detected

    Tornado is a Python web framework and asynchronous networking library. In versions of Tornado prior to 6.5.5, the only limit on the number of parts in multipart/form-data is the max_body_size setting (default 100MB). Since parsing occurs synchronously on the main thread, this creates the possibility of denial-of-service due to the cost of parsing very large multipart bodies with many parts. This v

  2. Jun 17, 2026 · NIST NVD

    Updated

    Tornado is a Python web framework and asynchronous networking library. In versions of Tornado prior to 6.5.5, the only limit on the number of parts in multipart/form-data is the max_body_size setting (default 100MB). Since parsing occurs synchronously on the main thread, this creates the possibility of denial-of-service due to the cost of parsing very large multipart bodies with many parts. This v

Affected

  • cpe tornadoweb/tornadoversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2026-31958

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2026-31958

    Tornado is a Python web framework and asynchronous networking library. In versions of Tornado prior to 6.5.5, the only limit on the number of parts in multipart/form-data is the max_body_size setting (default 100MB). Since parsing occurs synchronously on the main thread, this cre

    nvd.nist.gov

References